on #3 I strongly suggest checking out vBSEO
sure, you can do a majority of the basic things vbseo does with existing hacks and about 2 hours of your time (if you are good and quick) or you can install vbseo and have all of that and more setup within 15 mins.
Don't forget about the vbulletin upgrades, vbseo will be here for a long time and upgrades and the new updates are fabulous and very easy to preform.
You'll find many out there that just plain out hate vbseo and do everything they can do distort the fact, for the real answers you should ask on the vbseo forums and make the judgment yourself
I don't start a forum without vbseo, and I don't suggest a forum to my friends or clients without it as well

It's a small price to pay for assurance in the fact that your forum is as optimized as possible.