priorities from 1 (low) to 5 (high):
--- before starting -----
(5) First and foremost, battery is likely dead and damaged. I wouldn't even waste time charging it. You would be under the illusion that it works. I wouldn't trust one.
(4) Remove old fuel and change to fresh fuel. My biggest concern would be that despite having 43 PSI pressure in the injectors, they may be clogged. I would not worry about spark plugs. Start without touching the throttle. If it doesn't want to, start with wide-open-throttle (to signal ecu you are trying to unflood it). If nothing works, if injectors are clogged, I can only guess what to do next...
--- after starting ----
(4) brake pads and disk: make sure you don't have a major rust cancer on the disks (one that doesn't go away after the pads are tried to rub off the minor top layer). A thorough inspection of the calipers (all moving parts) is required. The sliding pin might be jammed.
(3) engine oil change: here it's not going to prevent starting, but you would obviously change it anyway right?
(2) brake fluid: 4 years is not a lot. It's the service time that's all. Better safe than sorry.
(1) tires: they will be ok, they won't "explode", but may have lost some grip. I ran on a 16 years old tire for an emergency change on a trip. It was fine, but I was told to expect less than optimal grip. I finished using it all anyway. So I wouldn't recommend changing tires, not worth it.
(?) coolant, fork oil: I don't have a clue what could have gone wrong in 4 years unused. Coolant/forks are in a closed system and you didn't add mileage. So, you be the judge. About forks: check they are still shiny and that the seals don't leak.
Needless to say, a typical inspection wouldn't hurt, bolts are easy to check. Cables easy to lube.