So do we think that the alkaline batteries could be the cause of the problems I've had or a drainage issue? or neither :-)
The Alkalines are your problem. The later OM bodies, the OM-PC (OM-40), OM-4, 4T, and 2sp will not work right with alkalines, the camera draws too much current for alkalines to handle and it causes the mirror lock up problem because the camera thinks the battery is dead. You must use silver oxides. Don't use the 3 volt lithium cells either, they give the same issue as the alkaline.
Fine Art Photography of Indiana and other places no one else photographs.