Yep, DL has MSEP! Fireworks depend on when you're there. What are your park dates? Outside of high seasons fireworks run Fri-Sun weather permitting.
You have the general idea of WOC. Sometimes, I think you can get standing space without a FP but it won't be "good" (there will be people standing in front of you). Keep in mind a WOC FP doesn't affect your ability to get a ride FP right away in the morning, WOC FP are "disconnected" from the rest of the system. Now, a FP doesn't guarantee even a halfway decent view, unless you get there an hour or more ahead of time to make sure you are at the front of your FP section. It's entirely possible to have a family of 6 feet tall people standing in front of you. Will they let you in front? Yeah right! (Obviously that doesn't happen all that often but it IS possible. More common is the parent who puts the short kid on their shoulders right in front of you.)
Reserved Seating (aka the Dessert party) will give you a nice view of WOC. It's expensive but I can't recommend it enough! Did it, loved it. Not squeezed in touching parts of other people you'd really rather not touch, straining to see over the people in front of you, camping out ahead of time and standing after a long park day . SIT back, have a glass of champagne, & enjoy the show in all it's beauty!