Well good luck, since its for hobby use then you will probably find that you are continually tweaking and changing things anyway

If you are worried about thermal effects then you will definitely need the consider dynamics as well, beam/column frequency and moving masses etc. just adding more mass can lead to resonance not to mention problems with accel/decel.

As with the thermal effects I suspect that the small size wont be to much of an issue but might be some thing to look at on your pursuit of perfection.....

Have you ordered the C1 precision ground ball screws yet?