My mother's a nurse and says floating is always a sign of too much gas. Although mushy poops and bits and pieces will oftentimes float--I think this is just because there's not much weight to them, not because of gas, necessarily.
Yes, hemroids can make you feel funny things around your rectum. The best bet for getting them to relax is to not strain to have bowel movements (i.e. be constipated) and also not to spend too much time sitting on the toilet. If you have D and have to spend a lot of time on the toilet, it's better to have a session, get up, hang around, and then sit back down than to just stay sitting there the whole time--sitting on a western-style toilet puts strain on hemmies.