OIL and WATER !!

I snapped a rusted bolt in the engine block....I snapped only a few threads I believe off of one of the two long bolts that crank down the water pump. How long are these bolts usually? Is there anyway I can bypass taking it out since I am trying to avoid having to take off the timing chain cover? Another darn question is that whenever I start up my car or drive it cold/anytime it appears the oil filter is leaking but i cannot tell if it is the filter or the pan..I need some help on these two fellas so in advacne I thank you,
- SCRAG