Good to hear everything went well
1. INPA is factory debug tool, it could present more info than pa soft, but you have to know what to look for
2. The GUI is nicer in pa soft I guess, but I'm used to INPA layout, haven't spent much time with pa soft
3. This could be in the shadow memory
4. Yes activate is to run some testing/reset subroutine. You have to use NCSE for coding, the same cable can be used for NCSE and GT1
One advantage is that with the right cable you can access more models than what pa soft allows. Have fun!