Version-named mod folders aren't supported anymore is the reason, since the launcher's Installations feature allows you to set gamedir (the folder that has the logs, mods, config folders in it) locations for each installation which does the job
The Forge installation created by the installer is bugged at this time, you should manually make your own and select Forge from the game version dropdown.
You can only have one version of Forge active at a time, so you have to find a version that all your desired mods are compatible with (usually the most recent version is the best choice).