Oil Leak

[Kneale Brownson]

Does the bolt with the arrow in this photo
http://www.pbase.com/image/31120869   have anything to do with the oil pump
housing being anchored to the block?

I have an oil leak that seems to commence just above this bolt.  I'm
wondering if operating the engine with this bolt loose might have
compromised the oil pump gasket, allowing it to leak even after the bolt is
retightened????

How about the bolt that anchors the alternator adjustment bracket (the one
with the teeth)????