As was mentioned, the only guests who are allowed to pool hop are DVC members who are staying at a WDW using their DVC points. Even they (we, because my family are DVC members) are not allowed to pool hop at Beach Club or Animal Kingdom Lodge. During busy seasons (like between Thanksgiving and New Years), pool hopping is suspended. Even during times when it is generally allowed, DVC members may be unable to pool hop or asked to leave if the pool is busy.
The zero entry pools are Grand Floridian, Polynesian, Saratogo Springs and Animal kingdom. All the pools with zero entry features are supposed to have wheelchairs that can go into the water. I have not seen them, but what has been described was not one of the PVC water wheelchairs, it sounded like a rust proof metal one. Some people have reported wanting to use the zero entry pool and being told there was not a water wheelchair available. Hopefully, that has been fixed.
Saratogo Springs has one hot tub with a lift. My DH said he saw someone also being lifted into the zero entry pool with a lift, but I have not seen that.
Other resorts (including Coronado Springs) have 'bump steps' in at least one pool area. They are useful for people with certain disabilities to help them get into the pool. I think the actual name is 'tier steps', but we call them bump steps because it kind of describes how they work. You park the wheelchair next to the top step (which is wheelchair height), transfer over to the step and then bump down step by step. They are not useful for someone like my youngest DD who has issues with sitting balance and also goes into extension when she's excited - with uncontrollable motions of her arms and legs (think of an ironing board that could flail 4 legs around while being stiff as, well, an ironing board).
As the others said, you could ask about whether it would be possible to use the other pool (you would probably need to ask at your resort and again when you get to the other pool. They are likely to say no, but you won't know if you don't ask.