I’m one of the “oldies” on this forum. I’ll try to help with the standing issues.
I cannot just rise up from a standing position unless the height is 22″ or more. For lower levels, I have to use leverage to push myself up, very low positions is a struggle or I need an “arm up”. My toilet is 19″ high and I am able to get myself up with no difficulty by using a good sturdy arm rail. One that wraps around the toilet is needed, rather then grab bars on the walls. I went through alot of falls (always have a plan in your head about how you can get up) and they stopped after the second year.