I'll take a run at some of these. My answers are in bold, omitting the questions I didn't have a good answer for.

Quote
My server runs on Apache and it has MySQL and PHP installed. I will try to find out what versions, but I would assume they are the latest since I pay for a dedicated server with a big hosting company.
Rember: PHP 4+, MySQL 4+

General Questions:

2.) A few years ago, it looked like UBB was going to die. Infopop changed their name and tried to push the Groupie thing. At that time I talked to several people at Infopop and they indicated they might have a new down-loadable forum soon.

I assume that this didn't happen and instead UBB.threads is the newest and best down-loadable forum from Infopop/Groupie? Is that correct?
UBB.threads 7.0 replaces both UBB.classic and UBB.threads v6. Threads 7 is the ONLY downloadable being developed with Rick at the helm

3.) Will UBB.Threads be developed and have a long life?
Unless Rick gets hit by a bus tomorrow....

4.) For those of you who used to run Classic, how do you like Threads?
That depends on the point of view and what features you valued. Personally I'm satisfied, but I just need to tear myself away from my schoolwork and figure out how to do external authentication (Hint Hint Rick - Authentication APIs)

5.) What features do you lose by switching from Classic to Threads?
User Notes for sure. I can't remember the rest right off - I've been using Threads 7 too long

6.) How stable has Threads been so far?
I participated in the Private Alpha and it has been stable

7.) Are there any security issues with Threads?
Currently, there are no security issues that I am aware of. I tried to do stupid stuff during the alpha to break things and get around security


Installation Questions:

1.) OK, so I'm no software expert. The MySQL things is really the main thing that worries me. So what would it cost to have someone install it for me? And what about the cost for uploading my classic data?
The cost depends on whether you have Groupee do it, or if you hire someone from the boards. A few of the moderators here are available for hire

2.) Once installed, how long does it take to export my files from Classic to Threads? I've read some horror stories on this site and I can't afford to be down for more the 4 to 6 hours in the middle of the night.

That depends on the amount of data and the speed of the server

3.) What's the best way to export without down time?
It is not possible to migrate without downtime, unless you are OK with losing some posts in the transition. You could possibly cause a corruption issue on your classic board if you try to import without closing it.

4.) Can I have Threads look exactly like Classic? My members are used to the "look and feel" of my site and if they detect any changes, it will cause trouble.
The sidebars and threaded mode are optional. The top and bottom navigations bars IMO, are better than both classic and threads

5.) I use HTML in the header and footer, can I do the same thing with Threads? You can see my site here: http://www.ffcobra.com/cgi-bin/ultimatebb.cgi
This is possible


6.) I don't need a calender, shout box, portal, etc. So do I have to use these things?
No, the features are optional

7.) I noticed the fonts on this site are hard to read, so can I set the fonts to match my current site?
This hasn't changed. You can customize colors and fonts using the CP Style Editor


Post Install Questions

1.) Will my members be logged in when they go to the new site? Or will their cookie not work and have to log in? The reason I ask is because I have 11,000+ members and if they are not automatically logged in, they may not know their passwords and it could be a nightmare for me.
New software = new cookies, so yes they will have to login again

2.) What happens to the linked pages? My site has many cross linked pages. Since Classic would be turned off, would this create a bunch of dead pages?
There are redirect scripts provided in the importers

5.) Are there any limits to Threads? I have a busy forum with hundreds of new posts a day. We average 1 new post every 2 minutes. Will there be any file limits?
Threads uses MySQL database, so you are limited by MySQL, not the number of files.