Alright, so my question is, for example, If I have a level 15 tank and then a level 15 caster, How will I box this through dungeons?

I understand how macro's work, and I plan to use the Priority macros for both of them, my two questions are:

What tank would you recommend I use? Does it not matter?

And 2nd, How would I arrange my team? I don't want my caster to... follow my warrior after he charges to an enemy. I understand I can just break follow, but that requires me to switch to the slave press a key, then switch back, between each pull