Decisions..Decisions...On FP Reservations..

There are viewing sections for Illuminations right beside the port of entry gift shop. All the times DH and I have been in Epcot after FP+ was introduced, we have been able to get awesome fireworks viewing from anywhere in WS, without a FP+. I would not personally ever get a FP+ for illuminations because there are so many better, less crowded spots anywhere in WS. Pick just about any country in WS and you'll have a good view of Illuminations.

Wishes FP+ viewing is worth the FP+ At least once. It's in the hub.

I would not waste a FP on Illuminations as you can get better viewing areas without it. I say this because I did in May and we were both so disappointed. If you didn't get there super early you didn't get one of the view good viewing areas. We had to keep playing peek/poo with a tree and it wasn't just us...everyone around us was complaining. So my advise use your FP for something else. And like Annielovesdisney said Wishes is worth doing at least once.
Just keep in mind if you use one of your 3 FP for fireworks you will not be able to get another one..if needed because you have to use the 3 first. When we did the all very disappointing Illumination one we waited until later in the afternoon. Of course this was May so I don't know if that would always work..waiting that long but again don't waste one of your 3 FP for Illumination...my opinion anyway.
Good luck and let us know what you do.

Do your three fastpasses for the rides you can't miss out on and try to set them up for earlier in the day unless you are park hopping. If you are starting out at MK but plan to go to EPCOT or Studios, I would set up your fastpasses for one of those parks later in the day because the good rides won't be available when you get there.

We have done FP+ for Main Street Electrical Parade (which is essentially a FP for Wishes as well because you are not required to move out of the area) and for IllumiNations (back when there were no tiers--it was heaven). I actually liked the vantage point for IllumiNations, but now that it's a tier 1, there's no way I would choose it over Soarin' or Test Track. The WS Lagoon is 1.3 miles around--plenty of other places to watch from. As for Wishes, I didn't really care for the vantage point from the MSEP viewing area. It was perfect for Celebrate the Magic, but it was too close to see Wishes properly. Our favorite place if we're doing Main Street for evening activities is right between Casey's Corner and Edys. That's where the walkway goes across and if you time it right, you can be right behind the walkway, giving you a buffer between yourself and the people in front of you--and save those precious FP selections for other wonderful attractions.