If I only book 2 of my 3 FPs at EP for FEA and Mission Space, then use both of those, can I then book my 3rd as a same day FP for another Tier 1 or do I have to use another Tier 2 first?
You have to use another tier 2. If you don’t want to use a second, you can let it expire if it’s before FEA but not if it’s after.
You will still need to use or let elapse (expire) a second Tier II fastpass before you are freed from the tyranny of tiers for your day-of fastpasses.
Once you’ve tapped in to your third fastpass of the day, you’ll be able to book the “rolling 4th” that is eligible for any tier of FP.
As others have said, yes. If you want to stay at Epcot.
If you want to hop to another park, then no. Just book the two, and as soon as you tap into the first one, book any other ride at another park.
Glad I read this, I just booked an early FPP for before I know we will arrive on the first day in hopes of catching a tier one FPP once we’ve done the 2 we actually want.