The bus system isn't too bad at Riverside.
There are four stops, South Depot (Front of the hotel), West, North and East. The Magic Kingdom and Downtown buses go West-North-East-South. If it is full at the South, then next bus starts South and goes around. Epcot / AK&BB / MGM go South-West-North-East. Depending how busy it is, there are also a couple of different variations first thing in the morning. There is a South-West-North-Park route, and a East-South-Park route which helps things. Typically, we only use the South first thing in the morning after breakfast if going to a park, and always just use the stop nearest our room. If you have an issue with standing, then you should try the South depot, not that guarantees you'll get a seat of course.
Again, depending when you go, buses to Epcot, AK&BB, MGM will go to French Quarter first. Magic Kingdom buses are split. Downtown&Typhoon (although there is the boat down to DD) go to FQ after they've done the reverse loop at Riverside. Returning from Epcot at night you may well find that they split FQ and Riverside into individual buses.
Articulated buses are also on order and are to be operating on Port Orleans routes, so again, that should help things.