1. Yes the pool will still be open. It will be nice outside in October, but will still be warm enough to swim. Anyway, the hotels normally keep at least one pool heated and open during the winter.
2. Did you book your reservation online? If you did, they let you select what room type that you want. You can either get their standard, standard strip view, Widescreen room (Nice!), widescreen strip view room, or spa room. If you can, I would definitely get the widescreen room. A strip view would be nice, but it costs extra and you won't be spending very much time in your room. If you request a certain location or room, they cannot guarantee it. I usually end up with a room that is staring at a wall on one of the lower levels. If you ask for a strip view, it will be considered an upgrade, and unless you get a clerk that is willing to give you a free upgrade, they will tell you that it will be however much per night. But it never hurts to try and contact them, especially closer to your stay to get a better room.
3. I love their casino. Their slots aren't loose, per say, but they aren't extremely tight either. You can sit down and play nickel video poker with $5 (at max bet of 25 cents), and still play for quite a while. The cocktail waitresses are great about coming around, even when you are playing nickel games. So the free drinks are plentiful. There have been many times that I have been asked if I want a drink, even if I'm not gambling, just standing by a machine. But you have to be there when she gets back, and if you give her a good tip, she'll come back more often. We always see Tournament of Kings while we are there. It is only $60 per person and dinner is included. It has knights and horses and jousting, it's fun. They also have a kids midway downstairs that is full of carnival games. They are all affordable ($1-$2 per game for however many balls) and they are very easy to win fun prizes. If you have to bring back any souvenirs, that is a great place to win them.
4. I love the location of Excalibur. It is connected to Mandalay Bay and Luxor, and across the street from New York and MGM Grand. From MGM Grand you can either walk, take the bus, or take the monorail to anywhere you want to go. At least once during our trip, we like to walk from Excalibur all the way down to Treasure Island, visiting each hotel as we go, and back so that we can visit the whole strip. If there is anything specific we are doing at a specific hotel and we are short on time, then we take the bus. Here is a map so you can see the relativity of the hotels, Excalibur is 42... http://www.vegas.com/map_popup_strip.html
5. There are timeshare people all over Vegas including at the base of the towers at Excalibur (where you come out of your room), near the front of Excalibur, right when you get outside to the walkway to New York, right when you enter New York- New York, and right when you leave New York-New York. They are also located periodically down the strip. So if you don't feel like going to a timeshare presentation for free show tickets, don't let them pull you in. They usually start with "How long are you visiting?" Just tell them you leave tomorrrow!
Excalibur is my favorite hotel because the value for what you get is awesome. Don't expect anything ritzy, just something fun. Also expect to get lost in the casino for the first couple of days, just look for signs. The casino is very big, and it all looks exactly the same. I still lose my direction every now and then, and I have stayed there 4 times.
I really hope you enjoy it as much as I do!