I have a tip for leveling faster: hit level 21. No, really. The XP changes don't hit until the 21+ quests/levels. Once you get there, things go nuts. Also, you may be onto something. If this is your first group and you're already bored, you may be better suited to stay solo. It seems slow/tedious compared to soloing a good DPS class but you only have a naked char up through the mid-50s really. Once you hit 52ish and get enough talents to flesh out at least one line well and get some better gear to help things, it's painful at times, with some classes more painful than others. Once you hit the 60s and get some decent outlands gear, things start getting a lot more fun. Multiboxing is quite a lot of pain up front and then a lot of fun toward the end. It's not a quick-fix/instant-gratification sport.

[edit] Look up some of Skuggoman's boosting threads. He's done some with a 70 lock that might speed things up for you.