@ AdorableMogwai
But what happens when your opponent plays the mainline? Trying to mix the Yugoslav and the Classical variation is not a good idea. Do you have a line prepared against the Levenfish? Do you have something prepared in the line 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 O-O 8. Qd2 Nc6 9. O-O-O d5?
Any opening is fine to play. Against opponents of the same strength as you, you will do just fine. However because it is such a theoretical opening you will probably get outplayed by players who know the opening netter than you do. I guess you could make this argument for any opening though. Keep playing it though. Even if you get slaughtered in the opening it is always a learning experience.