What temperature should the inside of the salmon reach? And for how long?
Is 450F an acceptable preheated oven temperature?
How long per pound should salmon be cooked at 450F?
The baking time doesn't really depend on the weight. It depends on the thickness, and how well done you want it.
The FDA recommends cooking to 145F, but you'll probably find it a lot nicer in the 120-130F range. There's a lot of room for personal preference, so it's hard to be too precise. It doesn't need to be held at the temperature for any length of time. Once it's hot enough, it's done. If you don't have a thermometer, you can also simply check it with a fork, to see if it flakes apart easily.
I might try 425F but 450F would work fine too. Assuming you're baking it uncovered on a sheet, for typical filets around 1 inch thick, I'd guess 10-15 minutes. If they're extremely thick, maybe 15-20. But since it's so easy to overcook, and so much better when it's just barely cooked enough, and ovens aren't terribly precise, you should definitely just check early, rather than relying on a timer.
450 seems a little high. I would roast a 2 kg piece of salmon at 400 F for 50 min to 1 hour. Once the flesh flakes easily its done.