1. why can't I remove the main character from the team? is this temporary or just how it works?

2. in the recruit/treasure/summon/whatever it's called screen, there are only 2 banners ('treasures'? what is it called). it says "this treasure no longer has a special deal for newcomers" and suggests I draw on higher level treasures, but there are no higher level treasures. is this just because my level is too low?

3. is this game pvp focused or can I just pve?

4. do I need a good team for story or can I just do whatever I want, not too interested in pvp or big events (at least for now)

try to not use any fancy game terms because I'm new and I have 0 clue what I'm doing