Do I have to use Connect? Can I uninstall it?

No, you do not have to use Connect. To uninstall it, go to your system's Control Panel, choose Uninstall a program, find Connect in the list, and follow the normal uninstall procedure from there. While this will not affect the operation of your MAGIX software in any way, remember that you will no longer receive future offers through the Connect system.
another quote from magix

btw - just noticed the forum now gives 'originally posted by' for text with the bb code quote syntax [could have been doing thart for a while of course ]