You can definately self-study all your CPL theory subjects and average between 80 - 95%!
I did that a couple of years ago using Bob Tait books, which were excellent! Did the same for IREX using Bob Tait.
ATPL subjects are harder, but I've known at least three people who've self-studied ATPL and passed them as well.
Sadly, for DIVOSH, I don't have time, so I've self studied ATPL human factors and MET (over 80% for both) but will go up to AFT later on this year for the harder ones, and do Law when I get back.
Self study may not be for you, but is definately an option!
Cheers,
DIVOSH!