What should the texture.png height and width in pixels be and what should the <drawSize> be for a 1x1 chair and a 1x2 bed?
I would recommend looking at the core files for information like that. You can look at an existing image for the h/w and the xml for the object for the <drawSize>
Coords (x,y), where
x -width
y - height
if size not specified, then game set (1,1). It does not matter how many pixels your texture is, you can set 900x900 pi texture in 1 cell, with size(1,1). But for optimization purposes, do not do this. Take into account that 64 pi enough for one cell.
if drawsize not specified, then drawsize = size.
Drawsize get size. If drawsize differ from size, then try to stretch texture.
So, size its a base tex. size. Drawsize need only use to stretch texture.
For example. Size (1,1), drawsize (1,2). Textute will be stretched in height in 2 times.