My experience with hurthlings, mostly, is that you'll end up being Burdened/Strained for the early-midgame through probably level ~16 or so. Beyond that, you usually end up with enough St increasing gear/potions that you can get ahead of the encumbrance problems (also, your worn gear tends to get lighter as you move to artifact/higher metal stuff). If you're really concerned about it, the Porter talents do help a lot.
It helps not to be too much of a packrat, and to pay attention to where your encumbrance is going. Avoid carrying big piles of food (you don't need much as a Mist Elf anyway) and extra missiles, sis, etc. that you don't need.
Hoping to win with every class, doomed. Archer, Barbarian, Bard, Beastfighter, Druid, Elementalist, Farmer, Fighter, Monk, and ULE Priest down.