Front Derailleur: Probably over concern. I have used racing double derailleurs on triples with range 53-24T with no problem. If derailleur has sufficient snuggle factor (my term), it will probably work. Snuggle factor: ability to get close enough to seat tube to drop onto small chainring of triple setup.
Shifters: I am taking brifters off my new touring bike and replacing them with bar ends. Too many stories of being unable to repair brifters on road.
Tires: I have toured on tires from 20 to 35mm. I suggest 32mm as target.
Spokes: Stick with 36 spokes. Much easier to get parts if need repairs on road, and should be adequate for your needs. What I use. Certainly 28mm tires and 40 or 48 spoke wheels is a mismatch.