I dunno, I'd check your easier bases first. It smokes out the exhaust tailpipe, passenger side being worse so true dual exhaust and out the tailpipe? Or it smokes inside the engine compartment, around the exhaust manifold?
I say easier ideas first cause if your valve covers are leaking and it's dripping down the block onto your mannifold, could be your smoke right there, and the bolt being covered in oil could be from that. If the mannifold is cracked, could have caused a gap between the mannifold and block, so oil could seep into it, and if the seal is bad, could be a mixture of oil burning form that, and exhaust leaking out at the mannifold.
Depends though where the crack is. I'm just assuming its cracked around a bolt hole. I'm assuming that big black line in the first picture is your crack? It seems to go right at that bolt. Take the mannifold off and see if that exhaust port is significantly dirtier/carbon/yuck than the other ports.
I dunno about the valve seals, however if that piston's rings are done, that'd be allowing some blowby of oil. And in that case, if only that piston has some bad rings, chances are then yes your valves too have been developing problems, or at least some awful buildup.
Also, perhaps a means of 'seeing' a possible problem with oil and that cylinder, is a nice lazer temperature gun. Point the gun at each port of the mannifold right next to the block, if that cylinder is hotter than the rest, then you are probably burning oil in that cylinder since I do believe oil burns hotter than gas. BUT in a engine.. dunno if that method will neccessarily work.
