ok Thanks for the responses. It looks like:

1. Don't worry about rep. The only thing worth worrying the discount over is the epic ground mount, but even then the discount is less than a daily's worth at level 70.
2. Skinning and weapon skill WILL be able to keep up even with fast leveling speed.
3. Herb and Mining will not, so looks like I'll have to go back farm herbs and mining nodes at level 70 (or even 80 lol)