Questions about a shelf cage for rats?

I know I already asked this question, but a few more things came up. So first, I know I'm going to put vinyl tiles down on the shelves, but what should I put over them? I hear fleece is good, but can I secure fleece to the vinyl tiles with stick on velcro, or does it have to be sew on? How often do I have to change the fleece, as well as cloth hammocks and toys. How should I clean and disinfect the whole cage itself, It seems like it would be hard to wash and rinse? Also, it seems like it would be hard to get a water bottle to work, will they tip over a water dish, or pee/poo in it? And if I used 1/2 in by 1/2 in hardware cloth for the door, does it have to be powder coated? Also, when my rats get older, what are some ways I can make it easier to get from level to level ( normally I would use ladders, ropes, branches ect.)? thanks for answering my questions!