Each room actually can be completed with only that room's ability (and each was tested as such).
The order you listed above is considered to be the easiest order yeah, as both of the upper rooms (Crouch at the Top Left and Wall Cling/Jump at the Top Right) require some pretty precise jumps if you don't have access to other abilities. (Crouch Room without Double jump or Wall Cling requires a precise line up with the moving platform at the beginning; Wall Cling Room without Fire Immunity or Double Jump requires lowering yourself a lot before jumping into the fire-hall, and then very quickly getting onto the safe wall).
I'm hoping that we can release a post-jam update that better fine-tunes the controls, and then we can tweak the levels a bit from there, making them all feel more reasonable when they are your last room, while still feeling challenging!
Yes but how can you get to those rooms without the double jump? You have to go up these glitchy moving platforms and without a double jump, I don't think you can get off them. Maybe with a perfect wall cling off one but timing the wall cling on the moving platforms is ridiculously hard.
People who want to finish this version just list it as "possible" and use my strat to see the (short) cute ending.
Did some testing you can get up to the wall jump portion without the double jump but if you complete the wall jump and go down to complete the fire it's impossible to get to the crotch section.
Edit: after many many attempts you CAN get to the crotch section with only crouch. Just really really hard is all. So don't be me: be efficient with time and follow a simular guide to mine :/
