[rdonj]

I got as far as opening the recruitment screen and got "cannot open ./mods/./Commonwealth/LightSpear1.tga".

Which of the mechs were you having trouble with? Was it just a specific kind or was it all of them? I'm not sure they should be untiring, because theoretically there's a human in there piloting it. If nothing else, adrenaline is going to take its toll on you eventually.... More soldiers would be good though, Jomon doesn't have a whole lot of variety as it is.

The only insectoid unit that can operate normally in space is the male, so you need to get up a good number of normal queens early on. Also, try using drones as your front line in space too, they're fairly hard to hurt as coccoons and it will keep more of your males alive. And remember that queens can summon males with the summon allies command.