You should be fine dumping everything but fixer and toners.
I would mix spent developer with stop bath before dumping the stop, to counteract the acidity of the stop bath. A wee tip I picked up from the Kodak data sheet on the matter.
Your local government (city or county) will have a way for you to appropriately dispose of fixer, toners, and other chemicals. You can take in all your other hazardous waste at the same time, such as batteries, oily rags, automotive fluids, electronic waste (which should never be sent directly to a landfill by placing it in the trash), empty spray paint bottles and paint cans, old paint and construction chemicals that you don't want, household cleaning products, etc.
It can't do any harm to take everything in to the waste disposal facility either, even though it is perfectly fine to dump developer and stop bath (and unused fixer) down the drain.