Yeah, most all inland lakes in central Florida are sink holes and are pretty shallow (wish I'd never bought that bass boat with a depth sounder). The typical live aboard sailboat would find a LOT of bottom in most lakes. That includes East and West lake Toho and last I saw, no liveaboards. Sanford does have a real nice marina and one I'd have recommended...in the '60's and '70's. If you want to work in Orlando, the traffic is very heavy and would be a GOOD hours drive from Lake Monroe.
The power boat traffic on these larger lakes are intimidating and bothersome. The commute from Kissimmee into Orlando is as bad, if not worse than Sanford into Orlando. Both are going to take in excess of an hour.
Another option might be out SR 528 (the "Bee-Line" or "Beach-Line" as it's now called). Toll expressway toward the coast, so with a "SUNPASS", it's under a 50 minute commute from the south side of Orlando. There are a couple of marinas just off the Beach-Line and are connected to the Canaveral Barge Canal that connects the Indian (ICW) and Banana Rivers to Port Canaveral and the ocean. Harbortown Marina(321-453-0160) is the nicer and is a full service marina. (I have no connection) It's closer to the lock that allows access into the Port.
Being a nurse, I would think you would be most welcomed in any Central Florida city that is close to the Orlando/Kissimmee area. Titusville and Cocoa do offer a live aboard a better opportunity to do some actual SAILING, more than any of the big lakes ever will... I hope this isn't too much of a downer, it's just the way the traffic jumbles.
Good luck with your search.
BTW, on hwy. 520 close to Cocoa, there's a large hospital (Canaveral, IIRC) that sits on a man-made island close to several marinas. If ya think of it as a big houseboat, you can live and work on the water!