New to mountain bikes but willing to learn

[djsb]

So, I've gone and bought myself a Montague Paratrooper Pro (20" frame). It needed to be a foldable so that I have the option of folding it away in a corner somewhere and so that I can make it easier to carry up 3 flights of stairs.
The front suspension is SR Suntour XCM HLO with hydraulic lockout (and preload) 100 mm travel, hardtail. Tektro Novela disc brakes front and rear, Chainset SR Suntour XCM. 42/32/22 front. Alloy 170mm crank arm, Rear Shimano Deore with 13-34 (CS HG200) cassette. Noname (as far as I can see) 32 hole rims with CST Critter Knobbly 26 x 1.95 tyres front and rear

My first priority is to optimise the ergonomics so that the bike fits me better. I'm 6'2" and 15 stone so i want to make sure that i'm as comfortable as possible.
Here are some initial thoughts:
a/ Fit a set of Humpert Ergotec AHS Premium handlebars. Not suitable for offroad use but I will not be going off road intentionally (some minor road dirt tracks and that it).
b/ Fit an adjustable handlbar stem so that I can adjust the height and angle so that my back is comfortable.
c/ Fit a more comfortable saddle. I have a Brooks saddle on my Galaxy, may fit another on this but may look a bit odd on a mountain bike.
d/ Fit a better set of 26" wheels (with eyleted rims-Rigida maybe). This depends on when/if I'm going to fit a rear hub motor or a Rohloff rear hub and front hub motor.
e/ Fit a pair of Avid BB7 disc brakes.
f/ Better tyres with less rolling resistance.

Next I want to optimise the gearing for the hills I have around here so that I can climb them easier without electrical assistance. I generally only use the middle chainring on my Galaxy (36 tooth Deore FCM510 chainring I think).
I would love to invest in a Rohloff rear hub if it would make it easier to climb hills. Still doing the research on this. My original idea was to just install an E-Bike conversion kit on the bike and have done with it. I would still like to do this but it will take me a while to research what is the optimum setup for me is and customise the battery/motor/controller so that I'm not carrying too much weight.
So I've decided to make the bike as comfortable and safe as possible first before going down the electric route (much more research needed for this).

Thanks.

David.

[hamster]

With a 22T up front and 34T on the back you have gears low enough to climb trees. Personally I would run the existing wheels to destruction before replacing them. By then you will have a better idea of where you want to set the weight / strength trade-off.