Post install 8.1 Clean install issues.

Initial info to help explain issue:

I built a machine for a clinet with an 8core AMD, 8GB memory 120G SSD (boot) and 2TB data drives. System installed with no issues and boots very fast about 7 to 10 seconds.

The issue lies in configuring his software and apparntly many incompatibilities with IE 11 the base for the Win 8.1 install. The following are problems we are encountering:

1. If I leave IE 11 as an active windows program when we load Firefox and set it as the default browser IE still tries to opem all browser links.
2. My customer uses AOL 9.0 and when the installer executes it identifies the browser (IE) as not being the correct level and it reports it as 5.x.
3. I attemted to put an icon on the Star Menu (Tiles) for the desktop version of IE, I have been doing this for my clients with 8.0 but with 8.1 it keeps executing the Windows AP Version of the browser (the one with the address bar at the bottom and no icons for minimize/close in the upper right).
4. Web mail from godaddy is also having issues in this instalation he can see mail but when he tries to compose or replie the pop-up comes up blank and has just the blue busy circle displayed.

Any solutions and suggestions would be welcome. I have a client that is growing increasingly more digruntled with 8.1 because it is hindering his ability to get work completed.

Thanks