...Remove the water pump and timing cover. It's not that bad of a job. Take some pics as you go along so that you know how things go back together. Get the broken bolt out. If you have to drill it out, get a set of reverse drill bits. Get a new bolt, all of these bolts should be grade 5 or better. Replace any of them that are not grade 5.
As mentioned, this is a good time to inspect and replace if necessary the timing chain. When you reassemble, check to see which bolts go into the water jacket - those get a little dab of RTV on the threads to seal them up and prevent those drips and drops.
When you are taking it apart, for whatever reason, there is about 5 different sizes (or more) of bolts used. Make a sketch and keep track of which bolts went in which hole.
As for the oil leak, sometimes those gaskets on the old filter are stuck to the block and don't come off with the filter. When you put the last new filter on, did you oil the gasket before screwing it on? It helps to get a good seal.
C
