Disney had superior entertaiment than the other lines we have done....and also food. We have cruised with HAL, RCI and Celebrity.
You can avoid the characters if you want. They usually have a central place they gather for photos.
You have assigned seating and rotation. It is noted on your card. Ours was LAP...Lumiere's, Artist's Palette, Parrot Cay...and they just rotate through in the same order for dinner. Lunch and breakfast is open seating.
You can book Palo's online when your time frame comes up for shore excursions and such. 75 days for first time cruisers. 90 days for
Castaway Club members....and I think DVC. Not sure on that. I didn't know about it.
You can book one dinner, one brunch and one tea....any more you want you have to do onboard. There is a $15 charge for dinner and $10 for brunch and tea.
Food and drinks are included....not alcoholic or designer coffees

And you had to buy snacky foods like candy, popcorn.
There was only one character breakfast.....and they did do some entertaining a couple of times at dinner. Because there is a finite time for meals, they do not stop at all the tables, so easy to avoid them. Pluto only stopped by us because of the bows

We did not cruise on DVC points. We don't have enough, but there were a few that did. Most don't think it is worth it. I guess that is a personal choice.
There was 3 meetings for DVC members. They gave out things and had drawings for more items and we would get messages on the phone to come by the desk to pick up pins and such. It was a lot of fun.
they gave us DVC magnets, hats, lanyards, a pen, tattos for pirate night and pins.
The cruise line gave us lithos....special Panama ones and a trinket box.
The biggest extra expense for us (besides the souvenirs) was the tips. They suggest a flat rate for room host, head server, server and assistant server. That varies by the length of the cruise. And tip at Palo's.
Depends on how much you drink

I imagine some bar bills were VERY high.
Spa treatments are also extra and shore excursions.