I brought mine from Manafont but payed a lot more, now the difference is $17.80 usd more to yours, i did not have a moisture problem with long runs or the spring problem or discoloration.
My driver base is different to yours mine is flat with no nylon ring and just uses a spring direct to the battery. I am also pulling a lot more current then your's and still have not melted the spring, but i did break off the tip of the spring, but the torch runs fine still.
Ive never had any flickering or any bad smells or driver or tail cap plunger discoloration any moisture problems and Ive had mine a lot longer then yours....
I believe 1.97 to 3.4 amps should not cause these problems as Ive drawn more amps then that through similar springs with out discoloration of parts or melting any thing and 3.4 amps is only approx 0.4 to 0.6 amps more then the TR-3T6 on 2 x 18650's that ive run a hell of a lot.