I've taken the Lynx bus from TTC to SW. It was really very easy and pleasant. Just be sure to tell the driver when you board that you are going to SW. You will be dropped off at the parking lot entrance. Just cross the parking lot and you're there, at the main gate. To get back to the TTC, just cross the parking lot, cross the street, and you'll find the Lynx paw print bus stop sign to your left. Easy.
As far as getting from SW to Universal via the bus, that's nothing I'm interested in doing. Too convoluted. It's not direct, there are changes to be made. You could probably get a cab from there though.
The time we went to Universal from WDW we hired a towncar for the 4 of us..it was the easiest way to get there.