I'm at a loss why you would block off the weep hole. The front bearing isn't intended to be submurged in coolant.
I'm also curious if the motor is run, wouldn't this small pocket of air get pushed out? It's a venturi pump so I can't imagine air not getting worked out from the turbulance. Seems unnessisary to me to add a bleeder. Not to mention this isn't the high point of the coolant system.
Velocity of the coolant in the system doesn't need to be fooled around with most of the time. The thermostat is the big bottleneck (as it should be) and overheats are usually radiator / airflow problems.
Or that underdrive pulley.
