timing belts and engine wear
 

I bought a 2011 Crown Vic with 300k miles 12 mos ago and I'm wondering how to approach servicing the timing belt. I know very little of it's past maintenance records other than what I've done with it this past year. Basically I'm wondering if I should go ahead and attempt to replace it now, or wait til something starts to go wrong. I don't know how timing belts typically go bad...if they just break or start to stretch or what. If this is an interference engine I'm imagining a fairly bad event so I'd like to get educated and be pro active about it.

Second...Scotty Kilmer teaches that the worst wear an engine sees after changing the oil is before the oil gets pumped back into the filter and then into the engine components during the first engine restart. But he says if you disable the ignition spark somehow when cranking for the first time again, the lack of combustion in the cylinders helps with reducing this kind of wear quite a bit. I don't have an owner's manual and I'm not sure what fuse to pull to disable combustion ignition, or if removing a fuse would be the best way to do this. Any opinions on how this should be done?