Hi! Sorry for the delayed reply - I somehow completely missed your message.
Thanks for the detailed feedback! I’ll get those bugs fixed ASAP.
About guardians joining your conquest: there’s a dialog that pops up right before you destroy the planet. The guardian offers to join you (or other scenarios) if you choose not to destroy it. Also, destroying planets gives bonus Dark Matter on ascension, which is especially worth it the first time. The bug you ran into is probably making that dialog skip or fly by too fast.