Good project. I like the marquee, and agree the side art could be a tad bigger, but i like it too.
I have found that hole saws are not very good at drilling through MDF. the sawdust packs up between the hole saw teeth and the holesaw quits cutting, so it starts getting hot.
If you use a hole saw, I think it is best to drill a little, then remove the saw and clean out the teeth. It is very time consuming, but sometimes you may have to use it for big holes if thats all you got. (A shop vac works good for cleaning the teeth, unless the saw is hot enough to burn the sawdust, then you have to use a toothpick or similar to get the crusted dust out of the teeth.)
I have found a spade bit cuts through mdf pretty good, but you need a piece of scrap beneath the piece being drilled or the bottom of the mdf piece may try to splinter when the spade breaks through.
I have also found spade bits do well on plexi, if you clamp the plexi between two pieces of wood and drill through one layer of wood and through the plexi.
But by far the router is the best, following TopJimmyCooks procedure.