Nova Solarius

Fair enough on the battery. I'm curious though, what was the first version of the cone like?

Is it just me, or is the guidance nose cone terribly powerful for a starting part? Compared to the Octo at least. The spoiler includes a little table comparing the Octo, the GNC and the Stayputnik. I suggest lowering the temperature resistance to 1200 Kelvin (the internal maximum of the MK.I Command Pod) and reduce both the power usage and capacity to bring them more or less in line with the stock units. Removing the SAS wouldn't be a terrible idea either.

Yes, it has been asked before. Fairly sure there were no plans to allow for radial attachment. Something about a design choice if I recall correctly. As for 5m parts... SpaceY Heavy Lifters has plenty. No command modules, though I believe it has adapters. 5m seems to be rather uncommon for the time being. Speaking of which, do you know where I can find some reasonably powerful 5m reaction wheels?