Can a kinked trans cooler line cause engine overheating?

The absence of the thermostat is definitely it my problem, because the thermostat has always been installed. In fact, I was wondering if maybe a piece of that RTV I found at the filler neck was stuck somewhere in the thermostat, preventing it to open all the way.

I was squeezing the upper radiator hose trying to burp it when it appeared. I’m thinking the squeezing may have freed it from the thermostat.