This probably should go in the Analytics forum. Anyway: yes, if you 301 this page it won't be properly counted by Google Analytcs (GA from now on).
The GA javascript checks the parameters in the URL and uses what it found to asign the campaign and etc. If the javascript doesn't load (when you do the 301) it can't check the parametres. If it does but there's no parameters, it won't be able to asign the correct campaign.
Solution: block your campaign URL's in the robots TXT. No link juice? Yes, no link juice. If anyone knows a way please post it.
BTW: they're not Google Banners, they're yours. You have control whether you want them to be indexed or not. Google has no right to decide it.
