This isn't good. For many reasons, not the least of which is that by not having separate partitions, you're unable to upgrade in the manner I described earlier. Having dedicated swap space is a very good idea, regardless of how much RAM you have. Personally, I've run into problems when using ext4, so I'm still using ext3 on all my computers. As usual, YMMV. I don't know. But I do know that if I were you, even though it would be a hassle given how your drive ISN'T partitioned, I'd take the plunge and do a clean reinstall, this time making sure I did it the preferred way. Back up everything important, then wipe the drive and do a clean reinstall, that's what I'd do!