Yes, you can get your wristband at the concert. You may either skip the concert and walk over and get in line, or I believe, they escort the group from the concert at 6:15. I think it is really just more crowd control than a chance to enjoy the concert.
If you aren't rushing to get a table, you can stay as long as you want and leisurely stroll over.
I know there is a big discussion about seating at PFTS.
We didn't find it a problem at all. We didn't want to be seated at a table.
We used the cocktail tables in the area that we were grazing. Never had a problem finding one to stand at. These tables are meant to be "pit stops". A few people tried to hog them for just themselves, but that isn't the intention.
I felt fine sharing with anyone wanting to stand with us. One couple looked at us like how dare we when we stood at "their" table. Room for 6 people. But everyone else we joined, or who joined us, seemed to understand what the standing tables were meant to be.