Sounds like a pretty good gig, I retired from a display company before coming back, it's kind of like that.
You lost me at dance floors though... If someone slips, falls & gets injured, doesn't matter how or why, even if they're just drunk and fall down, if it happens on that graphic, the liability goes to you. Spot graphics are one thing, but covering a floor opens the liability door a bit too wide for me.
For wall murals, most venues and commercial buildings with high traffic use silicone based paints for easy cleanup today, and graphics don't stick to them, so if they need to have murals or any other wall graphics, do some tests before you commit. What material to use kind of depends on what the walls are (drywall, block, concrete...), and how long they'll be up for. If they'll accept vinyl and are fairly smooth, Mactac Wall Noodle or Roodle would be among my go-to's for temporary event stuff, doesn't require lamination, 6 mil lays easy, and comes off easy & clean.
Another option for short term, especially if they have paint that won't accept vinyl well is fabric banners rather than wall murals. Cost would be comparable but It'll save them money on labor to apply and remove them, plus you don't have to worry about adhesion, or peeling paint off when you remove them. Everyone loves a cost saving alternative, and fabric banners look great. But that's just me.
The rest is just decals, use any temporary removable vinyl unless it's going to be there long term. Chairs too? Really? Never had anyplace ask for that. If they're going to sat on or leaned against I'd use a removable that has a little more aggressive adhesive for those. Nuthin' worse than getting up off yer' seat and having a vinyl tail