Sorry to hear about your troubles.
Sounds like the biggest issue was the subwoofer fire/smoke.
Was the subwoofer they used an AC or DC powered unit?
Usually a powered subwoofer has its own fuse.
As to the Suburban furnace, it is the most widely used furnace in the industry. You could have had that problem with any manufacturer. Sounds like they got it trouble shot and fixed, so that's good.
Now that you are good to go; Happy Camping!
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW