The rubber bands shouldn't stay on longer than a few hours when you wash them. If they stay on for days or weeks on end, you run the risk of them being sucked into the lock. They can and will rot inside and can cause mold problems. But they really aren't needed at all. They do more damage than good if you leave them in long term.
And palm rolling only does 1 of 2 things. 1) It will do nothing. if you notice, you need to palm roll them every day or so. This means that none of the times you rolled them did anything. They just get frizzy again. So why do it. It won't harm them if you only do it once in a while and lightly, but that bring me to #2) If you palm roll every day for even 10 minutes a day, you can and will irrevocably destroy your locks. I have a video of me showing what a few weeks of palm rolling has done to my locks. They are 6 years old in the video and still are so damaged at the roots that I worry every day about them snapping off just from their own weight.
Palm rolling might seem like a good idea because a few people say it is, but in the end, you are actually rippin gout hairs that are needed make your roots strong. Then you are rolling them and tangling them into the lock. What this does is add more weight to the lock because every hair stays in the body of the lock. But while you are ripping out those hairs and adding them to the body of the lock, you are ripping them out of the root system that is supposed to support that weight. As time goes on, and you keep ripping out hairs and not allowing the root system to thicken up, you run the risk of the lock just falling out because of the excess weight. It might not seem like much at first because 1 or 5 hairs aren't as noticeable, but in a year, you will see that your roots are SO much thinner than the lock. This is a bad sign. Just that weight being pulled on such a thin root will prvent your lock from moving freely enough to tangle with other hairs to strengthen the root. You will have to go to artificial means to wrap loose hair around the root and pray that in a few months it will be tangled enough to start fixing itself. But like I said, after 6 years my roots on the 4 locks that I palm rolled in the beginning are still so thin and the lock is so thick that I expect it to either fall off on it's on in a few years or be yanked off in my sleep at any time