Can newer main valves go bad?

mchema

I replaced my main valves 3 seasons ago. Last season we had a house fire. The system was put under a large amount of stress. It ran non stop since there were large holes in our house from the fire. This year I got the boiler serviced. Everything checked out. But I noticed the system is off balance. Our living room (really the whole downstairs) is freezing. so I upgraded my C goton valves to D. Down graded the radiator in the thermostat room from a 5 to a 4 gorton. So the downstairs is freezing and the up stairs is blazing hot again so I switched out all the #6 for #5. No change. I have 4 #2 gorton straight valves 2x antlers like I said all new 3 seasons ago. Could all of the construction and over working of last season clog the main valves? Because the system is action like it did before the mains got replaced. 

JStar

Vents

It's not unheard of. What pressure is the boiler running at?