Coolies, at present I can only use the alpha on my shammy healer as I use grid to heal so the frames are just there to look at
On my dps toons though I have to disable the alpha as I need the button timers to help me time my debuffs
As to the grid scenario. The extra flexibility that it gives you is the reason I switched to it from healbot. Whilst I can use the nUI unit frames to heal with my mouseover macros the extra information I have grid telling me helps me decide who has priority.
The addition of a white/black list will be cool as well as the decurse like ability. With grid I also have a tank/aggro marker so that I know who to concentrate on and these are words/borders more than icons.
So that I am not inundated with lots of spots on the frame I usually place hots all in one corner and whitelist all the known hots ( regardless of who casted them ), that way I know they are receiving heals and can concentrate on those that aren't.
Note though that grid allows us the user to define the spells to see and where. I think this is what some if not most people are asking for rather than you account for every spell possible.
So lets see hmm what do I need to see
The ability to see whether there is a debuff I can remove
The ability to see whether there is a debuff at all so I can heal them while it is waiting to be removed
The ability to see hots ( regardless of who set them up and what spells they are
) - Yes a tough one there
I am sure there are others but those are what I thought of at the top of my head. Understandably there is a limit to what you can put in that small space. So I am still not sure how it will work in comparison to grid.