If pressing cycle makes the unit fully drain, and it doesn't seem to struggle doing it, I'm thinking its more of controller issue. You didn't post brand or model so can't confirm, but does the controller also tell when to add the rinse aid? Because you mentioned that stopped dispensing as well. The hoses look correct.
As for the smell, try running an.empty cycle on the dishwasher with a little bleach, and drain it immediately after. Then fill with clean water and drain again. As for the smell in the disposal, what worked for me when I had that issue was filling the sink with hot soapy water, pulling the drain, and letting the sink empty completely while running the disposal the whole time.