I've just got a cardboard cut out to the right shape with a yard stick taped to the back to support it and the ends taped to the light fixture to not allow any undue air to pass through. The light bar that I have is just a bit longer than the tank (that's by design) so that I can hang one end of it off the back to limit heat and humidity escaping and cold air getting in but still allowing for air flow. Pretty soon I'm going to use plexi glass and some kind of rubber sealant as a permanent lid, but that's going to take a weekend's worth of engineering and troubleshooting to get right.
Good idea on the emergency sheet, here's the final results:
1. What kind of substrate is used in your tank and how deep is it?
A: I use play sand from home depot (washed thoroughly) and Eco Earth at a roughly 5:1 ratio and it's just under 5" deep. Once my molter comes up I'm gonna redo it all and make it deeper this go around
2. Do you have gauges in the tank to measure temperature and humidity? If so, where are they located and what temperature and humidity do they usually read?
A: I have a dual Temp & Humidity gauge on the middle right of the tank that consistently reads about 80ish F and because of the scrappy lid I need to spritz about 3 times a day usually and it fluctuates between 50-80 (don't hate me I'm trying to fix it xc)
3. Is a heat source used in the tank? If so, what?
A: Yup, medium heat pad stuck to the back left hand side of the tank
4. What types of water are available (fresh or salt) and how is the water treated (what brands of dechlorinator or salt mix and what ratio is used to mix it)?
A: FW & Salt, I have dechlorinated water in my house that I use and the salt water is currently the bottled variety from the pet store, will be using "Soaking Salt" that you manually mix with water once I run out of the bottled kind, cross that bridge when I get there
5. What kinds of food do you feed and how often is it replaced?
A: I feed them the crap looking Zoo Med Hermit Crab Food pellets in a bowl then sprinkle some lettuce and apples around the tank for them to look for
6. How long have you had the crab and what species is it, if known?
A: I've owned Tamatoa & Possum for 3ish weeks and Rocky, Apollo & Racer for 2 days, No clue! No Idea how to tell the species!
7. Has your crab molted, and how long ago did it happen?
A: Possum is currently molting (hopefully, he's been down for 2 weeks now) the rest of them are above ground, except apollo, he's shy and only comes out at night.
8. What type of housing are the crabs kept in, what size is it and what kind of lid is on the housing?
A: They're kept in a 36 gallon bowfront aquarium 30x15x21. A really crappy cardboard one but I'm doing my best ;-;
9. How many crabs are in the tank and about how large are they?
A: 5 in total, Tommy is large, Apollo is just a bit smaller than him he's in the medium range though, Rocky and Possum are medium, and racer is a small little boy
10. How many extra shells are usually kept in the tank, if any?
A: 6 but Tommy has already tried 2 of the larger ones before choosing the ones he's in now so the rest definitely won't be using the rest any time soon becasuse they are definitely too big for the rest of them
11. Have there been any fumes or chemicals near the crabitat recently?
A: Nope they live in my bedroom
12. How often do you clean the tank and how?
A: I haven't had them long enough for a full deep clean (substrate and all) but I dig around for hoarded food once a week and replace the obvious "scavenge" food every 2 days
13. Are sponges used in the water dish? If so, how are they cleaned?
A: I have sponges from the KK that I got them with in both bowls and I clean them once a week by just rinsing them out under cold water for a minute or so
14. Has anything new been added to your crabitat recently?
A: Only crabs and the decorations, but I rinsed dunked them in boiling water before adding tghem to the tank (the decorations, not the crabs lol)
15. Is there any other information you would like to share that might be helpful (anything that is regularly part of your crab care, playtime, bathing, etc.)?
Not that I can think of, I would really appreciate any input you have on my setup and how I can improve

I'm still new and I'm really interested in these guys and want to provide them the best care I can.
Attached tank pics for clarification:
Full Tank:
Heater:
Temp & Humidity Gauge:
