1. Does the SQL script just execute an update on the DB? If so, then nothing gets deleted or overwritten that would contain custom data?
No DB change.
2. Can you do the upgrade wihtout having to replace chat.aspx? If not, would you suggest I just try to find and copy over my custom changes from my current chat.aspx?
You don't need to replace the chat.aspx
3. I have the chat software on a custom theme in CS. Do I need to worry with the theme files/folders you provide in the install?
No.
4. Do I need to worry with the global.asax file from the upgrade?
No.
5. Any other advice on upgrading to V4.1 with CS 2007?
a. Copy the new DLLs
b. Copy the client files
asp.net Chat http://cutesoft.net/ASP.NET+Chat/default.aspx
Web Messenger: http://cutesoft.net/Web-Messenger/default.aspx
asp.net wysiwyg editor: http://cutesoft.net/ASP.NET+WYSIWYG+Editor/default.aspx
asp wysiwyg html editor: http://cutesoft.net/ASP
asp.net Image Gallery: http://cutesoft.net/ASP.NET+Image+Gallery/default.aspx
Live Support: http://cutesoft.net/live-support/default.aspx