1) No, No, Yes as long as you haven't implemented any of the new features. (Although RI and stored procedures may not be "shared" by VFP 6.0/7.0 applications.)
2) For the most part yes - there may need to be minor re-works of code here and there (similar to the VFP 5.0 to 6.0 upgrade).
3) Almost no changes here, so I guess it depends on how good you are with the VFP report generator. (See Cathy Pountney's articles in the December '00, February '01 and March '01 FoxTalk's for proof that there's almost nothing that can't be done if you're just a little creative!)
4) While there are some new functions and extentions to some old ones, some are referring to the langauge changes more like 6.5 rather than 7.0 <g>. There are also a number of useful changes to developer IDE - these may help or hinder you depending on your coding "style".
5) Yes, but they don't recommend it if you plan on installing the REAL VFP 7.0 on the system. Since the uninstall of the beta is (in some cases) less than satisfactory - especially if you install all the beta .NET stuff, you may want to put it on a separate system (or different bootable partition).
6) Yes, after all that's what the beta process is all about - testing out code both new applications (.NET enabled?) and upgraded "old" systems. But of course since you can't distribute any VS.NET or VFP 7.0 code yet, it really shouldn't bother your customers.
7) As a beta product - Yes. As a production product - No!
My $0.02 worth,
Rick