Hello, my first post so be gentle. I will offer advice as best I can.
1. Yes you can buy blank decal paper for you inkjet printer, I have bought it in the past from Squadron.
2. For the pinstripe I would paint the gold on first, a few thin coats with the AB. Then mask the stripe and paint my white then blue sections, again carefully masking them. Tamiya masking tape is a must have here.
3. Use CA on the etch but a medium viscosity along with an accelerator this will allow you to move the part around a little before the glue sets then hit it with the accelerator and the glue will set instantly. Just remember the fumes will hang around on the part so wait a while before sticking any more PE in that area as it will set on you straight away. I use a pair of good quality cuticle shears from boots to cut the PE from the fret, then sand the gate remnant away with flat nosed pliers and a sanding stick. It is a good idea to anneal the parts before painting, this involves heating with a ligher then cleaning up once cool. Always prime the PE parts once fitted at the same time as the styrene parts to get a consistant colour.
4. A razor saw is the best option to cut the canopy, put masking tape on first to avoid the canopy splintering, I always fill the part with plastacene as well to stop it distorting.
5. Your idea for the arrestor hook seems spot on to me.
Good luck and I hope I have offered good advice.