We went for SOTF last year in March and it was very cold. We needed thick coats, hats and scarves. It also rained most days so I’d take a waterproof.
I’m sure the Star Wars nightime laser show in the studios started 15 minutes before closing, so you were leaving at Park closing time rather than starting at closing time as Illuminations does.
And full board is 2 vouchers which have the same monetary value if you upgrade to a higher category restaurant. On their own they are valid for the same level of restaurant so you can either use them in a quick service restaurant (but that will be less than their face value) or at a buffet. We went in Restaurant Des Stars in the studios a couple of times for a buffet lunch and really enjoyed it. It was a big hit with my kids, even the eldest who is a super fussy eater!