I play BattleTech but rarely read the setting information bits. I've always treated it like a strategy board game. Though, I've read a few novels and followed product releases over the years, but never read any of the setting material. Not even in the Technical Readouts. Still, I think I have a pretty good feel for the Setting thematically.
I own AToW but prefer to develop a homebrew system (easier for my 8, 10, and 12yr old kids to grasp) that uses the BT Setting. There is also the possibility that I just use a different RPG system. I plan to mine AToW for goodness, of course. I'm just not able to picture what kinds of adventures you could run in BattleTech, that would allow you to have adventures outside the cockpit. I'm curious to hear what kinds of things you guys are doing, when you RPG with BattleTech?
you can literally run ANY adventure you want in the setting with the AToW system. AToW is not a setting per say but a rpg system that plugs into the battletech setting.
for example you could use "d20" palladium, gurps, D6, shadowrun, the new star wars system, the warhammer 40k rpg, or any number of RPG's to play in battletech heck you could even use FATAL or hackmaster if you really wanted to.
what is happening is you are confusing the rpg with the setting. which is a fairly common confusion I believe.
for instance I long ago played star wars using the WEG (West End Games) D6 system, and honestly I much prefer it to this day to the newer wizards of the coast D20, and or saga edition version of star wars.
what the RPG is frankly is a ruleset that you use to setup "how" you are going to play in a setting and what conventions you are going to use to play/simulate the experience.
the setting is the background and environment you insert yourself or your characters into to have fun.
so if you prefer to use another rpg "engine" to play, the biggest issue you will have is figuring out how to adapt or convert the stuff from system A to system B
for example lets say you chose to use the palladium RPG to play a "battletech" game no problem, you just have to decide what the "scale" is IE are mechs sdc, MDC, or some other damage scale, how much damage does the battletech themed weapons do etc.
as far as using the battletech setting its a mish mash of stuff ranging from cyberpunk or shadowrun level tech (but no magic) to literally places (and planets) where the most common transport is you walking, or if you are more well off you might have a horse or xeno-horse to ride. heck you can also literally have planets where in a major city it resembles Coruscant in star wars with "air cars" flying between buildings, or to use another example... the city Bruce Willace was in, in the movie the fifth element.