You certainly don't "need" that many drums, but if you're up for leveling Leatherworking then i'd definitely suggest doing it, it wouldn't hurt. Netherstrike is also preraid BIS, along with Windhawk being nearly as good but a bit more flexible in later phases.

The radius on drums isn't really a factor since it's not as if you're going to be spreading out your whole team that far while doing heroics. You can also manage just fine with lust, drums would just be an added bonus for the more difficult trash pulls and for burning down bosses faster.

As for secondary professions, those would be up to you. I'll probably just end up doing Enchanting on all 5 of my Shamans for the SP ring enchants, and to d/e all the BoP quest rewards they get later once i'm 70. Though i may run at least Mining and Skinning for the initial 60-70 dungeon grind, but it's not something i'm especially worried about. I'm not too interested in the herb / ore nodes in dungeons, as gold is going to be easy enough to earn as it is and i don't especially want to add more to my heroic runs.