I can sometimes spend as much as half of a 60 minute match just getting from cadet to warrior, so I know what you mean with that part.
Other times I seem to rack up point like there is no tomorrow.
I dont like marshes, mainly because of all the damn trees you keep getting suck in or which blocks your movement about 70% of the time.
Its really annoying to when youre about to finish off your opponent only to run onto a tree and get stuck with no chance to fight back as your opponent just shoots at you from a "blind" spot where you cant shoot back.
Mirage are my favorite, with the canyons and stuff makes for diverse tactics.
You can sneak around behind the enemy in passive mode and surprise them from behind,
while its still possible to get close enough to brawl should one want to.
Frostbite, Sandblasted and Clearcut are ok maps.
I find Sandblasted to be a bit too open though, and the games tend to turn into poptarting or LRMfests.
Clearcut and Frostbite has decent cover options even though they can sometimes turn into the same as Sandblasted, fortunately that dont happen so much.
Tunder Rift, is a nice map indeed, though battles tend to be in the same place every time and that gets boring in the long run.
Also if you fall into the water you usually have no idea where to go to get out, and you can see jack under the water even though the water is not very deep.
Even turning on your headlights dont help, you cant see 3 feet ahead of you.
As for the LT, the only times I had problems with the LT are when I'm standing still or moving in a big slow mech.
I normally dont use it myself, as its difficult to aim and hit with slow as hell to move and very vulnerable.
And it only takes 1 or 2 LRM volleys to take it out.