Well sounds like your camshaft is worn out and it is not opening the valves. This will cause the presure in the engine to be very high I would replace the cam and lifters. I would also replace the valve guides in the heads. Also run a 180 degree thermostat. this should fix your engine heating problems.I hope this helps you out.

Sounds like a bunch of things, bad rings, bad valves, bad head gaskets. A motor should not have that much blow by and usually when it does it is time to start pulling it apart. You can do a few things like check compression, and related blown head gasket tests, but a worn out cam is likely the least probable cause of overheating, blue smoke, sound much worse then that sorry to say. BTW this is all speculation you really need to spend some time and start with simple diagnostics like compression, leak down if you have the gear, radiator pressure check can show head gasket and other leaks if not holding pressure, check oil for white-ness (water in oil), etc. Pull the valve cover and see if things are working as they should. Pulling the thermostat is NOT a good idea you need a restriction in the cooling systems where the T-Stat is, and a 180degree should be used in any case, but it sounds like other bad things are going on.

It sounds like you have some severe issues with blow-by and/or head gasket seal:
an easy way to check for possible blown head gaskets is to remove the rad cap with
the engine running. You could get anything from bubbling coolant to actual expulsion of the coolant out of the rad neck under pressure (even without excessive engine temps). And of course, a compression check/leakdown check would also be in order.
As already mentioned , not running a thermostat is a bad idea, but your other issues
need to be addressed immediately 'cause without correcting them, presence or lack
of a thermostat is a moot point.