[David Fix] "Will any NLE on Mac or PC be able to use these files without having FCP?"
IF they support P2. Avid does, Adobe Premiere does, Edius does. Not sure about Vegas. But the rule of thumb is to ALWAYS back up the original media. DO NOT import thru an NLE for use in another. Most NLEs import/convert into manners that only that NLE can deal with.
[David Fix] "If client or 3rd party wants to upload to youtube/vimeo or insert files into, say, a PowerPoint is ProRes still the best solution?"
No. Never was. ProRes is the best option for editing in FCP. For exporting for use in Powerpoint, MP4 or H.264...or in the cases where I deliver it to clients with PCs running powerpoint, .WMV. YouTube and Video want H.264.
Shane
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