Hi,
thanks for your detailed problem report! I am aware that on certain (most of which PowerPC) setups Morgana is misbehaving quite badly, and will definitely look into each and every one of the problems you describe. The complicating factor is that no matter what I try I can't reproduce any of these problems on my test rigs--by which I don't mean to imply that they're not there, just that that's why they haven't been fixed yet.
If necessary I'd like to contact you privately with a beta build to see whether it fixes your issues--if that's OK with you of course. For starters if you could send me a crash report from DP (either through PM or by email) that would be very helpful to see if I can infer anything from it. For the moment I can only reiterate that I am fully dedicated to getting rid of these bugs, so if you'd be willing to do a little testing to pinpoint the problem I'm sure we can get Morgana 100% stable on your setup.
There will be both a 12 bit successor to Morgana and a separate 12 bit sampler, more details in due time. We will certainly offer an upgrade path for registered users for the former, and possibly--read: possibly

--a loyalty discount for the latter.
Take care & thanks again for bringing this to my attention,
-- dj!