Depends what you want. If you want to lose the most weight possible in a given timeframe, do everything. Much of what you drop will be muscle, but you'll get smaller, and you will lose a lot of fat.
Yes. The only way I've ever successfully cut was using this method. Minimal cardio (read: 6 x 20:40 sprint/walk intervals followed by 12 minutes of walking four times a week), heavy compounds lifted four times a week, and a caloric deficit.
Those are my abs in my 'tar. I was fat for twenty years prior to that.
You used too much volume. The workouts you do while cutting are short. Mine are usually something like one upper and one lower per workout, something like quads and shoulders for instance:
- 5x5 squats
- 3x8 front squats
- 5x5 cleans
- 3x8 shoulder press
- 20 minutes of post workout cardio, first six minutes are sprints
- stretch and go home.
Like I said above, you'll lose a lot of weight. Much of this will be muscle, but if you don't mind losing muscle and getting weaker while you cut up, it'll do the trick.
Remember, you have to burn off 3500 calories to drop a pound of fat, but only about 600 calories are stored in a pound of muscle. Train and diet wrong, and for a 3500 calorie deficit, you can lose six pounds, but you won't like it.