Knipster - I'm not T1 so can't really comment on many of your specific T1 related queries, but my post will bump your thread up the viewing lists a bit.
One thing I will comment on is the weight you have gained is likely to have been weight you lost leading up to diagnosis?
Years ago, after I had lost a lot of weight due to illness, when I started to regain it, it felt like it all went straight to my tummy. Being me, I had a bit of a moan about that to my Docs They just told me, it would take my body a little while to "spread it around", and for me, they were absolutely right.
Do mention it to your Doc or Nurse, if it continues to concern you. They'll likely understand.
Good luck moving forward, Knipster. It's a very steep learning curve for you, for sure.