Also curious if there are any other rules of what you can and can't have, I know several members have expressed interest in multiple bank chest (which I think I've heard is a no).
Although I'm not able to answer your other questions authoritatively (Funky will probably be by to correct my estimates below), I can say the limit is one of each kind of bank chest (so two total, one transfer and one personal).
Your estimate of a maximum of 108 tiles and 3 maps is also pretty good. Also, please try to keep the total number of placeables under 100, and the total number of usable placeables (not including the standard accoutrements, e.g. healing fountain, split chest, bank chests, and so on) under 10.