With some bots back on Nauvis, you can absolutely troubleshoot and even/improve fix stuff from other planets.
Of course, fortifications are important, and you should make sure you've got your factory fairly protected first
Without spoiling anything, all of the planets have different challenges that require different solutions to make stable. Definitely part of the fun is that you can't copy/paste solutions between the planets
I said the same but look at how the Raining Cats and Dogs precon sells used. I think I'm gonna buy one of these and see