As nobody from Genuitech has responded, I’ll take the liberty to answer your questions. As fas as I understand its a YES and a NO for 1 and 2 resp.
MyEclipse is already build on a “heavily modified” WTP. They plan to build on WTP 1.0 for their 5.0 release for which a first milestone is scheduled for early april. If they plan to do three milestone releases, we might see a final version of ME build on WTP 1.0 roughly somewhere near June.
In various other posts I read that installing WTP together with ME is usually not a good idea. I haven’t tried this myself.
Note that this is just how *I* understood things. Can’t guarantee anything 😉