That's a crash report from SMM, and it means that the manager can't find modorder.txt in /mods/ folder. Make sure that both exist.
The "calculate optimal offset" feature uses a formula that has been guessed based on offsets from vanilla ships, so it is quite possible that the offset may not always be exactly optimal for every layout you can dream up, but it should come pretty damn close.
Regarding the hangar image, I actually did entertain the idea quite a long time ago, but never went through with it -- I didn't know how to incorporate it nicely.
However, I'm currently rewriting the editor in preparation for AE, so it's quite likely I'll finally introduce this idea...
Lol, failed. But I fixed that a while back with SMM.