Greg,
Thanks for the answers (and it looks like you were up about as late as I was).  I did find a link to J. Bennets script to install Horde3, and it worked like a charm!!!  It automatically did the php upgrade for me.  I find horde alot slower than v.2, but it's doing much more than before.
With regard to question 2, that's what I was hoping to hear.  The only add ons that I'm using  (that I need) are fetch and backup2ws.  I'll check the status with them for v. 7, but I think they're both operational now.  I do have v.7 installed on a testing machine (I reported a bug with my D Link NIC), but I was afraid to apply to my production server in case I wasn't able to smoothly upgrade to the stable release when it comes out.   I thought I'd read somewhere that the beta versions will not upgrade to the release version.  Knowing now that I can, I'll upgrade shortly.
Thanks,
Rob