8A - look at the central letters in the words before "in the middle"
25A - Canvas = tent, pole = a bar, and a tentpole is a slang term for a high-budget movie (I was familiar with this term but I'm actually not positive how common it is after googling it, it's a thing in some circles tho)
18d - the state capital is Dover, with the D going after LAN
I believe 25A is just a charade; canvas = tent, bar = pole, and blockbuster being a definition (a big movie that makes money for a studio can be called a tentpole). 18D is Dover (capital of Delaware) and LAN (local area network) with the D moved "after". I don't understand 8A either.