As for automatic casting of Raise Dead, the only solution is: Cast Resurrect first, then choose Fix. (If you have the spell Resurrect).
Reading my copy of OSRIC says that any spell with a permament duration is open to dispelling, if the roll works out.
There seems to be no OSRIC version of the DMG, so I can't look up the 0 Constitution matter. But certainly in Second Edition, your initial Constitution is the maximum number of times that you can be revived.