I always believed that since 'Mechs are fluffed as being such awesomely efficient vehicles on the battlefield, at least SOME of that awesome efficiency ought to translate into use as civilian heavy equipment. I furthermore believe that there should be as many more civilian mech 'jocks' than mechwarriors as there are civilian pilots to fighter pilots in the real world.
That being said, a game about a universe dominated by big stompy robots should have more than the following backgrounds available:
1) The rich kid/merc brat who grew up around 'mechs and was groomed since childhood to enter the 'family business' of war.
2) The pilot who learned his trade at a mechwarrior academy
3) The gladiator
So here's a challenge: I'd like to see if the community can come up with at least 101 civilian jobs that could plausibly involve piloting some form of mech. I'll start us off with some jobs organized by broad categories:
Construction:
1. Drill Operator (whether digging tunnels or mines, the mobility of an industrialmech threatens to render wheeled/tracked drillers obsolete)
2. Foreman (I don't see the Kiso as being a one-off crazy thing)
3. Zero-G Miner (Mining asteroids is canonical.. and how better than from an industrialmech?)
4. Landscaper (while mechs wouldn't totally replace cheaper conventional heavy equipment, there are times the agility makes the price worth it)
5. Surveyor (IndustrialMechs are the ultimate all-terrain vehicle)
6. Underwater Welder (IndustrialMechs are also the ultimate amphibious vehicle)
7. Wrecker (see #4)
8. Pile Driver (see #4)
Agriculture:
9. Farmer/Farm Hand (liability laws, if nothing else, would allow more cross-operation of AgroMechs than IndustrialMechs. Or maybe they'd be broken down, too)
10. Mega-Fauna Rancher (Space Cowboy!)
11. Lumberjack (Logging is one field where 'mechs probably would render conventional vehicles completly obsolete)
Transportation:
12. Longshoreman/Dockworker (those guys who load and unload dropships, sea-going ships, and trains)
13. Loadmaster (the guy who's in charge of the cargo on board a dropship, sea-going ship, or train)
14. 'Mecher (what else would you call a trucker who drives a cargo hauling mech?)
15. Sub-Marine Cargo Hauler (mechs would be good for supplying mobile sea-surface installations)
16. Road Maintainer (mechs would be great for removing boulders & felled trees, as well as plowing snow in extreme climates)
Entertainment:
17. Professional Dueling Entertainment Performer (This is to Solaris what WWE is to wrestling.)
18. Monster-Mech Performer (monster trucks, only with mechs)
19. Pro Mech Racer (NAS'Mech, anyone? I can see the things covered in corporate sponsors already..)
20. Mech-Polo Player (polo seems like a plausible team sport that could translate)
21. Grip/Rigger (filmmaking positions)
22. Stunt Pilot (either 'barnstorming' or for film work)
Commercial:
23. Corporate Test Pilot (the first Solaris 'gladiators' were these)
24. Corporate Security (the difference from a standard merc outfit is the Status of Forces.. these guys are civilian employees rather than Military Contractors)
25. Strike-breaker/Union-buster (Just one messy way to put an end to a strike)
26. Foundry Worker (You could use a forklift to move around multi-ton castings.. or an IndustrialMech)
27. Police SWAT Pilot (In a universe where military gear is in the hands of private citizenry, the Police can't just make do with 9mms and flak vests)
28. Park Ranger (There is little better platform than a 'mech)
29. Fire Fighter ('Mechs might not completely replace the wheeled fire engine, but there IS a heck of a niche a walking fire engine could fulfill)
Criminal:
30. Mech thief (where there's something valuable, there'll be those who'll steal them. and the skills to 'jack a mech would be pretty specialized)
31. Gang Enforcer (Teddy K blew the lid off this one. Once he blessed the Yakuza's ownership of mechs, their rivals won't stand idly by)
32. Labor Union Enforcer (if there's corporations dastardly enough to have #25, this won't be far behind)
33. Mega-Fauna Rustler (even if the skillset were to be exactly the same as #10, it's still a completely different career)
34. Bounty Hunter (Just can't put that pesky MechJock in the enemy army down? Put a bounty on his head. Someone will eventually collect.)
35. Logging Poacher (Like #11, only without the permits & legal cover)
36. Gypsy Caravan Pilot / Canopian Pleasure Circus Carny (Setting up Ferris Wheels & the like goes alot faster with an industrialmech..)
Hobbyist (someone with enough money to be able to afford playing in or around mechs)
37. Historical Battle Re-enactor (Look at every air show you've ever been to. Someone is flying some personally owned WWII vintage aircraft..)
36. Orbital Skydiver (EXTREME!)
38. Cannonball Runner (illegal mech rally racer)
Entrepreneur
39. Junkyard Proprietor (what better way to stack, hack, or crush junk than with a mech?)
40. Battlefield Salvager (kind of like a lostech prospector, only you don't necessarily want just lostech)
41. Mech Repoman (the bane of every mech jock behind on payments to the bank..)
42. Prospector (sensors can be one helluva way to find nodes of minerals just underground.. and besides there's good hard mechanical work to be done dregding a river and so on..)