Ok, I've done some more testing when the next group of visitors arrived - this time I got three ladies and none of them was marked as a trader so none of them had the space and beauty bars.
This time I surrounded them with people, hiding only the two lazybones I've got in the colony as one of the ladies was a hardworker. Followed them to the dining room to eat together, followed them to the rec room on their initial visit to try and get some casual chat. Made my people drink a lot of beer and smoke a lot of weed to stay nearby, and then drink some coffee to stay awake. They must love it when the guests come around. Would have followed them to the bathroom if there actually was any (now that I think of it, it's kind of weird that the guests stay in bed ALL day and only go out to the dining room for a moment...) Still, using only your best negotiator to build relationships (if you manage their sleep time carefully) seems to be working best as you don't get any more "real" chances to improve relations anyway with more people as negotiators, yet you risk it will go back down if someone else tries to do the job and screws it up. The chitchat didn't seem to add almost anything to the pool as they didn't seem too eager to talk, I only got a couple of extra points for that even though everyone was around so they could pick and choose. I didn't get any deep talks but I did get one last time with Bidueiro, which boosted the relationship quite a bit - guess he met his soulmate there (well too bad, he wasn't good enough to be allowed in our perfect colony - AND his soulmate is already married).
Now the ladies weren't actually good enough for our perfect colony either so I didn't have the recruitment checkbox ticked but I was able to observe it took 25 total relationship points to get that "relationship too low to recruit" message off... That's a bar set very, VERY high if you don't have any pretty face around to show off.
I got the message turned off just a few hours before they left and still someone managed to insult that lady afterwards and bring the total back to 23 relationship points which was again too low to recruit... In theory, though, there would be a SINGLE chance to recruit this one person - which is still better than nothing. If there was by any chance a family relation there, it would have been a lot easier as there would be about 20 relationship points for a start - which makes a lot of sense. And if we weren't so average-looking, we would have had a good chance to recruit all of the ladies - which kind of makes sense as well. 
Regarding the points - my relations with this faction were at 59 points before they arrived and their expectations were high. I did manage to get them amazed but it took 25 points to get the "relationship too low" message off.
In my last sample, the tribe that came to visit had relations with us at 20 points and their expectations were low, yet the message was still on at 24 relationship points - which could either mean that the 25 points are a fixed value, or that the faction relations also need to be higher to make it possible to recruit someone. Still, it's good to have some kind of an estimated goal that needs to be reached. Now I need to get some pretty face to show off to the visitors.
I can imagine how easy it will go then...
"Hey girls, have you met Albert, the Model? Well here he is, he was just coincidentally cleaning the floor under your feet..."
"Did Cervexa insult you again? Oh, don't mind him, he's usually locked in the basement making pretty sculptures. Talking about pretty... hey, here's Albert, the Model, just casually drinking beer at your table. Why don't you talk to him?"
"Heeey, what a coincidence! You're going to eat something? Albert's also pretty hungry, aren't you, Albert? Oh yes you are, don't fool around and walk the girls to the table, off you go!"
"You're tired? Oh, what a shame... Well, Albert will make sure no mad animal walks into your room while you're resting, it doesn't matter he can't really fight, he'll just... well he'll just be standing there over your heads, just in case..."
Yeah... That would definitely work.
Thanks again for your help and good luck with the A16 version, I hope the feedback will come useful. I think I know a lot more about how the mod actually works now so I should be fine.
This time I surrounded them with people, hiding only the two lazybones I've got in the colony as one of the ladies was a hardworker. Followed them to the dining room to eat together, followed them to the rec room on their initial visit to try and get some casual chat. Made my people drink a lot of beer and smoke a lot of weed to stay nearby, and then drink some coffee to stay awake. They must love it when the guests come around. Would have followed them to the bathroom if there actually was any (now that I think of it, it's kind of weird that the guests stay in bed ALL day and only go out to the dining room for a moment...) Still, using only your best negotiator to build relationships (if you manage their sleep time carefully) seems to be working best as you don't get any more "real" chances to improve relations anyway with more people as negotiators, yet you risk it will go back down if someone else tries to do the job and screws it up. The chitchat didn't seem to add almost anything to the pool as they didn't seem too eager to talk, I only got a couple of extra points for that even though everyone was around so they could pick and choose. I didn't get any deep talks but I did get one last time with Bidueiro, which boosted the relationship quite a bit - guess he met his soulmate there (well too bad, he wasn't good enough to be allowed in our perfect colony - AND his soulmate is already married).
Now the ladies weren't actually good enough for our perfect colony either so I didn't have the recruitment checkbox ticked but I was able to observe it took 25 total relationship points to get that "relationship too low to recruit" message off... That's a bar set very, VERY high if you don't have any pretty face around to show off.
I got the message turned off just a few hours before they left and still someone managed to insult that lady afterwards and bring the total back to 23 relationship points which was again too low to recruit... In theory, though, there would be a SINGLE chance to recruit this one person - which is still better than nothing. If there was by any chance a family relation there, it would have been a lot easier as there would be about 20 relationship points for a start - which makes a lot of sense. And if we weren't so average-looking, we would have had a good chance to recruit all of the ladies - which kind of makes sense as well. 
Regarding the points - my relations with this faction were at 59 points before they arrived and their expectations were high. I did manage to get them amazed but it took 25 points to get the "relationship too low" message off.
In my last sample, the tribe that came to visit had relations with us at 20 points and their expectations were low, yet the message was still on at 24 relationship points - which could either mean that the 25 points are a fixed value, or that the faction relations also need to be higher to make it possible to recruit someone. Still, it's good to have some kind of an estimated goal that needs to be reached. Now I need to get some pretty face to show off to the visitors.
I can imagine how easy it will go then..."Hey girls, have you met Albert, the Model? Well here he is, he was just coincidentally cleaning the floor under your feet..."
"Did Cervexa insult you again? Oh, don't mind him, he's usually locked in the basement making pretty sculptures. Talking about pretty... hey, here's Albert, the Model, just casually drinking beer at your table. Why don't you talk to him?"
"Heeey, what a coincidence! You're going to eat something? Albert's also pretty hungry, aren't you, Albert? Oh yes you are, don't fool around and walk the girls to the table, off you go!"
"You're tired? Oh, what a shame... Well, Albert will make sure no mad animal walks into your room while you're resting, it doesn't matter he can't really fight, he'll just... well he'll just be standing there over your heads, just in case..."
Yeah... That would definitely work.

Thanks again for your help and good luck with the A16 version, I hope the feedback will come useful. I think I know a lot more about how the mod actually works now so I should be fine.

