Brake conversion.

1) braking technique for long descents: Don't feather your brakes continuously, brake harder, then let off. Less heat build up that way.
2) if you're getting heat transfer into the brake calipers enough to see brake fade, you should have at least equal concerns about what that heat is doing to your rim tape/tube/tire on a rim brake bike. Can you post a link to where you read that?
I've done mountain touring on both rim and disc braked MTBs, and in my eyes, discs are the clear winners.
3) Drop bars on a MTB is doable, but trickier than you probably imagine. All sorts of issues with getting levers to fit and be compatible with your brakes and shifters. Far easier tricks are either just to get a longer stem, or get a trekking bar. They'd bolt right on and stretch you out more forward.

Besides, I don't follow your description. Popping the front wheel up - sure, it can happen. Position on the bike, pedalling technique and choice of gear will contribute a lot to that.
But then there's that bit about spinning your back tire, and having to get off and walk.

These two are pretty much each other's opposites. To keep the rear from spinning, you want more weight there. To keep the front from getting airborne, you want more weight there. Can't have them both at once.

I'd say maybe a longer stem, and/or trekking bars, then work on a smooth, high cadence pedalling technique when climbing.
Also face the fact that the rider needs to move around to compensate for differences in riding conditions. That's why it's called riding - not driving...
Sure, it's possible to build a real good climber or a real good descent bike, but they'd end up suffering a lot in other areas.

Just did a net search on your bike. If it's like this one: quebecscoot.comshowthread.phpOpen ↗ - you do realize it's pretty much an overgrown BMX, right?
Phrase which keep popping up is "dirt jumper bike" and such. Seated riding was never a priority in the design of that bike.
Like a BMX, you're expected to the the overwhelming majority of your riding out of the saddle.
If you want good climbing, look for an XC(cross-country) MTB.

Yeah, that's my bike. Although mine is a little different than that, the down tube that seat post mounts in is a little longer. What would you recommend for cross country biking then?

[FONT= arial]You probably want to plan out your final configuration. If you are seriously considering drop bars, then hydraulic disk brakes probably won’t work because they don’t seem to make brake levers for drop bars. Mechanical disks would work fine. Cane Creek SCR05 levers are available with additional cable pull for the mechanical disk brakes. I have also discovered in-line brake levers. I have some Cane Creek in-line levers on my bike now because I spend so much time on the tops it is very convenient to use them, and if you are used to flat bars, they may seem more natural than drop bar brake levers. The best mechanical disks are supposed to be the Avid BB7. I have them on my Vaya and I really like them. Shifters will be another issue. Flat bar shifters probably won’t play on your drop bars. I like Shimano indexed barcons.[/FONT]

[FONT= arial]I think disks are a good option for a road bike. I would rather dump heat into the disk than dump heat into the rim where it could increase tire pressure and possibly blow the tire off the rim. Don’t worry. You are unlikely to get to that point. [/FONT]