Is it possible to run Vegas without installing the Sony Media Manager?

If so, does one need to install the NET Framework?

1. Yes - just hit cancel when Vegas tries to install the Media Manager - or if you've already installed it, go to add/remove programs and unistall it. Make sure you go into the "Preferences" (general) and un-check "enable Media Manager".

2. I don't think .Net has anything to do with Media Manager. But Vegas needs it to work properly.

.NET is required by other parts of Vegas besides the Media Manager. For example, Scripts require .NET. .NET is definitely a requirement for using Vegas.

As for the Media Manager, you can easily turn that off in the preferences. If it's already installed, you can also uninstall the Media Manager by going through the add/remove programs area of the Control Panel.