I've always gone by the loose rule of 10 miles per litre for mileage, which will obviously go either way depending on riding style, motorway riding, etc.
You have the 22 litre tank on your model.
I've always found the Haynes manual to be very good, there's an online version on this site, but you can't beat a hard copy.
Tyre pressures are a very personal thing, some people will swear by 36f/42r, whereas others are quite content with 32f/36r.
It also depends on your personal weight, do you carry a passenger, luggage, etc.
That's one for you to get comfortable with through experimenting.
Not really heard anyone complain about slow steering before, in fact it's quite unusual.
Do yo have a standard 110 tyre up front, or maybe a 120?
Either way it's not ever really mentioned on here that i can recall.
Sounds like the rear caliper may need a clean up or service, once they're in good working order and given the occasional spring clean they work just fine.
Other than that there's plenty of info on here if you use the search box, otherwise just ask away and we can point you in the right direction or try and answer what you need to know.