A couple of suggestions

[TrashMan]

1. Power managment.
In other words, the ability to control and easily turn on/off power to all objects of a type or in a specific area.
Something as a simple as a Power Control Station (that must be tied to the power grid), where you can for example instantly turn off all interior lights, set sun lamps to only turn on during darkness, auto-lock all doors AND set specific doors/lights into groups so you can turn them on/off separately from others.
That way you can easily cut power of a hab block, or turrets, without affecting the rest of colony.

2. INCINERATOR - for all the corpses and useless stuff

3. Ability to move larger debris pieces (would require 2 colonists to work together)

4. More various items and resources. Making carpets out of METAL is silly. Harvesting berry bushes without getting berries is also silly.
So many different things you can collect to build many different things.

5. More various types of alien creatures.

6. A general shooting skill + a specific skill for each weapon Prevents mastery of all weapons.

[IncognitoMode]

1. I think a power control system accessed via a building would be good.
2. Sure, why not.
3. Like what?
4. Yes, rocks should be able to be macerated for use in concrete to make walls, however I imagine the colonists can do a lot with their sonic screwdriver type things they build with.
5. Animals, including a ride-able Tauntaun like creture. but maybe not humanoid colonists...
6. Would be good but maybe a little complicated... maybe... not sure...

[Untrustedlife]

1. Power managment.
In other words, the ability to control and easily turn on/off power to all objects of a type or in a specific area.
Something as a simple as a Power Control Station (that must be tied to the power grid), where you can for example instantly turn off all interior lights, set sun lamps to only turn on during darkness, auto-lock all doors AND set specific doors/lights into groups so you can turn them on/off separately from others.
That way you can easily cut power of a hab block, or turrets, without affecting the rest of colony.

2. INCINERATOR - for all the corpses and useless stuff

3. Ability to move larger debris pieces (would require 2 colonists to work together)

4. More various items and resources. Making carpets out of METAL is silly. Harvesting berry bushes without getting berries is also silly.
So many different things you can collect to build many different things.

5. More various types of alien creatures.

6. A general shooting skill + a specific skill for each weapon Prevents mastery of all weapons.

Pretty much all confirmed except 1 and 6.
Also corpses will be considererd food (includinnghuman bodies). (Yum)

Also No real aliens exist in rimworld (they are all genteticlaly modified earth creaturesZ), so they won't be totally alien (no little green men) or parisites etc.