Not quite sure how well geared your pally is but I personally did boosted in ZF from 40-50 in shockadin gear with shamans dpsing and healing. Key is to find good places to LoS the casters and burn them down super quick. Once the casters start running though I use the shamans to snipe em all down as the casters won't stop running in fear and never reaggro your main. A problem definitely worth mentioning is that the "Shadow Hunters" in ZF can still hex your Booster toon which does not break on dmg and will cause your main to lose aggro while hexed for 8 seconds. To get around this I avoided pulling shadow hunters where possible, had a /target shadowhunter macro (must have exact mob name of course), and used a /cancelaura Divine Shield /cast Divine Shield macro which I saved on pulls with lots of hunters just in case they did get a hex off.

So other than casters continually running in fear and hexes I thought It was a great place to boost. The fact that you can mount up makes it easy to grab a large amount of mobs very quickly.