Temporarily emptying iPhone storage for video recording

Question

Hi,
Firstly, apologies if this has been asked on here before – if so, I couldn't find it, and might have been using the wrong search terms.
I'm getting married soon, and rather than hire a videographer to produce something we probably won't like anyway, we thought we'd go down the riskier route of asking friends and family to use their iPhones to record video on the day, and then editing all the results together ourselves.
The major stumbling block we're facing now is that most people's iPhones don't have enough free storage available to be used as video cameras for a day-long event. So I was wondering if there was any safe way to back up each iPhone (we're talking about half a dozen or so), temporarily reset it to clean out the storage, and then restore it later on after extracting the video. The questions I need answered are:
1) Can one Mac, running one instance of iTunes, be used to back up multiple iPhones, some of which are not even synced with that specific Mac?
2) Can I get large amounts of video off those iPhones without syncing and potentially over-writing previous back-ups? Is there a method of extracting video that doesn't involve iTunes (just as you can use Preview in OS X to get photos off the camera roll without opening iTunes, for example)?
3) Once the video has been taken off the phones, is it safe to assume that iTunes will happily restore each phone from its respective back-up?
Thanks very much for your help.

Answer 1

Sorry, there is no easy/foolproof way to do what you want. The biggest hurdle is the simple fact that by design, an iPhone will sync or manually manage iTunes content with one computer at a time. So, even if you successfully backed up each iPhone's content on a single computer, & restored such to each phone when finished recording(all possible), the content would then be erased again when these phones were connected to the computers they normally sync with. Are you sure each of these individuals can deal with this? Getting the videos off each phone won't be a problem...the problem is dealing with the other data & the deletion/restore process.
Edit:
You could have each of these individuals sync their phones on the computers they normally sync with...this will create a current iPhone backup. Then on each phone: Settings>General>Reset>Erase All Content & Settings. Record the video, you import to your computer, when they get home they restore from the backups they made. That would work.