Like was already said, the space overall is small, nowhere is "far away" from the stage. The most expensive seats here are the Premium, that are furthest away, that should tell you enough. The stage is also pretty low, so even if you end up in the seats right by the stage you don't have to look up too much.
The thing with the seats is, beyond the category they won't assign you a particular seat until you show up (I think). So whoever gets there first generally gets the "best" seats within that price category.
Btw, this is the seating chart: https://54below.com/seating/
So the ringside seats really is only the few tables right by the stage, or the tables in the "second row", depending which chart is used for your performance. I'd give them a call and ask to put a note with your reservation, that you don't want to be right by the stage. In my experience the staff there is really accommodating and friendly. They might even advice you to switch you Main Dining Room and refund you the difference.
I haven't experienced stars casually hanging out at the bar after the show, but plenty of times they'll be there for sign and take photos. People will que up, anyone can join no problem. If you're going to a 7pm show there's somewhat limited time because they'll have people coming in for the 9:30 show and they have to clear out the 7pm crowd before. But since the space is so small and only a small percentage will que for photos and autographs it still shouldn't be a problem. I got to meet Laura Osnes after her 7pm show without feeling too rushed.