OK let me see if I can help a bit.
E-nights - You must have a ticket to do this. The parks stay open (in a limited way, not every ride) after close and if you have a ticket (which you do have to buy) you get to stay! I am 99% sure this offer is only open to onsite resort guests.
There is an info page on the DIS site (there is a huge website in addition to these boards!)
PS-Priority Seating- Avaliable for all sit down meals, not just character breakfasts. If the meal is inside a park (like The Storybook Breakfast in Epcot) you also need admittance to the park. Anyone can make PS resservations, not just resort guests.
"Seats" for parades and such. The only one that really has seating that comes to mind is Fantasmic, and yes if you want to see it you need to show up early and get a seat (how early depends on time of year). For most of the parades a 'seat' is a bench or curb along the parade route... we don't seek out spots 2 hours in advance for parades, we get lucky and catch them sometimes but if I am going to wait around a long time for something it better involve a high speed drop or chocolate
Someone who likes to fight for a good bit of curb in order to see the parades might be able to tell you more about that.
Some links for you:
Menus (all of them) are here
http://allearsnet.com/menu/menus.htm
E-nights
http://allearsnet.com/tp/etik.htm
or for the DIS page with all sorts of park info links, go here
http://www.wdwinfo.com/wdwinfo/themeparks.htm
I hope that helps. Have fun making your plans!