There are different alpha flags. if you select the nialphaproperty and look at the block details, you should see a flag setting. its 237 that will certainly work at default. anyway. so you should just be good to go.
the 4844 isn't necessary. I would definitely use that in the circumstance, of say 2 objects in the same nif. both transparent. one overlayed on the other, the first use of alpha, the outer one would be like a hole cut in a cylinder, like a window. and would have no blending. 4844. the second would have blending. Zeta walls with windows, and plasmapistol for examples to examine. if you want to get confused at complex alpha set up look at the scope.nif. :S
no if you wanted 2 objects, both with alpha, and blending... its gets annoying.
you have to be very care with sort of this as the alpha is finicky. Alpha sorting. its drawn on screen according to vertex num. so on a single mesh you can get problems. accross several meshes you can get z buffer fighting. transpaent meshes blinking in and out when viewed at certain angles.
Anyway you should be good. as its straight forward stuff
I feel ya- modelling= super crack