1. Where are most of the "good" dive sites located?
Either side. I prefer the north but I'm a bigger stuff guy - I like rays, grouper, turtles etc. They're on the south side also but it's also much better macro diving.
And what dive operators go to these locations?
Most do some/all of them. Generally the north side shops ride around to the south side once or twice and vice-versa. Both locations also go east some distance depending on where you stay.
2. Are there any locations with good beaches other than West Bay?
Not especially. Sand Bay has a few areas but there's mostly residences/rental houses in that area - and Anthony's Key resort.
3. Is it necessary to get a rental vehicle or could we do without?
There's really no way to qualify that without a location choice. You can walk around the West End pretty conveniently. Same with West Bay. It's 2 miles between them. At night you wouldn't want to walk it as the road dips inland and there's been a few robberies.
4. Is A/C necessary in October? I'm from Ohio so it's in the upper 50's to low 60's in October here.
Probably not but you may want it to knock-down the humidity - esp. at night - October/November are the rainy season.
5. In terms of diving, what's the difference between the North and South side of the island?
The south side tends to be shallower, lighter, more macro. 2 of the better known dives Mary's Place/Calvins Crack are on that side. On the north side you've got Spooky Channel, Hole in the Wall - or sites around the far west point (Texas, Bucho's etc.) a couple of wrecks - Odyssey and Aguila. Cocoview has a signature wreck also - the Prince Albert. Doc has an excellent description of the south side around Cocoview he posts in other threads asking the same question.
6. Is it easy enough to get to the West end from some more remote locations like Turquoise Bay or CocoView?
Not really, both are pretty far east. Turquoise Bay:
We are 45 minutes from the tourist area of West End/West Bay which has a variety of bars and restaurants.
I honestly thought it was closer till just now - I've been by there on a diveboat. Cocoview is also on the south side.
I think so far from what I'm researching, and correct me if I'm wrong, what you guys are telling me is: The West End is pretty much out because there's really no beaches and it's mostly partying.
Most of the partying is IN the West End. A few minutes away from the West End is going to be quieter. Luna Beach would be. Here's the West End (Half Moon Bay) Beach. As you can see it's not very wide - the roofs in the background are bordering the road.
http://www.ronystours.com/images/we-beach2.jpg
West Bay is more "civilized" but it's where most of the tourist-y stuff is given that's where the cruise ships come in.
Maybe I wasn't clear on that - the cruiseships all port on the south side. Mahogany Bay is the Carnival cruise port/complex and some of the other lines dock in Coxen Hole. All the beach excursions ride up to West Bay since it's the best beach. Also some of the resorts - like Bananarama - solicit cruise traffic actively to enjoy their beach.
Most of the good restaurants are in either West Bay or West End.
Pretty much - as I mentioned previously, check the Trip Advisor link for locations.
To find the quietest/most relaxing locations you have to stay at one of the more remote hotels like Turquoise Bay or CocoView.
Pretty much but there are a lot of resorts all over the island - most have a dive operator. You might see if Parrot Tree Plantation is somewhere you'd be interested in - from the beach/pool perspective - it would be quiet there also. It's about an hour east of the West End though.
One last thing, if you had to pick one place to stay that really does "have it all," wp[here would it be? I know that question is vague, but put in terms of my requests. This is assuming price didn't matter. What location/hotel gives you, or rather me, most of the things you could want?
On the south side my overwhelming favorite is Barefoot Cay - it's also near French Harbor. I rented a house in the West End but my choice if not would be Cocolobo but there's no beach there (next door to the house I rented so I walked over once) I don't have a West Bay choice as it's not for me.