Hey man,

Don't worry, your idlemaster is working! This is a legacy from when Valve implemented a 2-hour wait before your first card-drop. To get around it, Idlemaster would idle all your games at once for 2 hours, then switch to 1-by-1 to get your cards.

If you go to File ---> Options, there's a setting which says "Idling behaviour". Switch it to the top option (Idle each game individually) to switch this off, since it's not needed anymore.

As for how long per card, it varies from game-to-game, but most games will spit out about 1 card per 30 minutes. Of course, there's also a few which do not do this (and I once idled a game which took a whopping 4 hours per card) so ultimately the only solution is patience.

Just remember not to play or run multiple games at once, as Steam will make the time go up exponentially per game running (about 2x the time per game running. So running 10 games means a 1-hour drop becomes 20...and so on!)