1. my '99 Civic SI performs extremely well in snow, has relatively low miles, is EXTREMELY rare (try to buy one), and has lost very little value over time. It's only caveat, why I'm looking at a truck is I need trailworthiness for trailhead access.
LOL! Sorry bud, but a 99 Civic SI is not "extremely rare" or worth much. It's a reliable little commuter car. You are right about the fact that it is a bad choice for a vehicle to make frequent trips up the hill in snowy weather.
2. I drive 30 miles each way to work everyday, and further than that on my days off, so the mileage adds up quick.
3. Does the slight advantage in the toyo mpg worth it for all these miles over an f-150? I do like the f-150 alot. What about a 4cyl toyo? Do they even have that in 4wd?
If you are set on a truck and care about MPG, get a Tacoma. It will outlast any F-150, get better mpg, will hold it's value much better, and will end up costing you less in maintenance/repairs long-term. I have owned a few Toyota 4x4s, and can tell you that they are pretty much bulletproof with basic maintenance.
4. Should I crush my truck dreams because of all these miles, drive my SI into the ground and just get another lil 2wd wonder with snowtires - fuck I'd go hybrid?
Why don't you keep your Civic for your daily commute and get a truck for your trips up the hill?