S7 has some chromium and other alloys that reduce it's susceptibility to rust.
A first rate bluing like the kind the 19th century custom rifles had is a good
rust preventative. So is a good polish. If you have both and exercise a little care you are fine. For the tropics you could have your pistol nickel finished.

Bead blasting makes steel more susceptible to rust so a bluing or patina over that won't do much good.

If bluing wears off you can simply reapply and it will blend right in.

I have seen an indian SMLE bayonet and a Parker Hale rifle that have incredible bluing jobs. The indian bayo is really poorly made though. Strange it has such a great finish.

A Parker Hale custom #4 is what you would get if you gave Ban a No4 Enfield and a blank cheque.