WowAce

I suddenly find myself in need of more action bars.  I usually run with 6 bars, 3 in the middle for combat, 1 to either side of those 3, and one at the top of the screen.  I never used bars 7- 10 but suddenly find myself wanting to use them for macro bars.  I'm going to use it on a druid also, and I saw that 7-10 are used for that classes other stances (assuming the same is true for various other classes as well.)  Is there a way to add more bars past those 10, or if I start moving stuff around will it affect my druid and what not?

You can't have more than the 10 main bars.  (Well, 120 main action buttons to be precise.)  That's a Blizzard limitation.

If you start doing weird things with bars 7-10, yes, it will affect druid forms.  The usual solution to this is to use different BT4 profiles for your druid than for the toons you want to do weird things on.  For example, a different profile for that specific druid, or for all druids on your account, etc.

On the BT4 profile configuration tab, you can also copy settings from one profile into your currently-chosen profile, so it's easier to experiment.