engine temp gauge getting to redline, no heat coming from vent

What is your question?

Subaru Impreza Wrx turbo 2005 model. 100k miles. 1) replaced radiator 700 miles ago after leak detected and engine overheating 2) car running fine since then even in 99 degree heat. Temperature stable and normal. 3) today after driving about 100 miles I noticed engine heating up to redline 4) steam starts spewing from upper radiator hose near the side going into engine pretty intensely 5) I replace upper hose (big gaping hole detected in existing hose near the side that goes into engine) seems like it was not replaced with new radiator. 6) after replacing upper hose, no more steam. However engine temp gauge goes to redline after < 1 mile of driving but no heat coming from heater vents on full blast even after idling for 10 minutes. 7) coolant reservoir is full and not going down 8) engine does not feel hot (like it would if it was really overheating and at redline) 9) no more steam coming (I fixed the main leak) in the hose. I doubt there are other leaks but it was raining so hard to tell till I get to a shop. Is the problem now that I need to pressurize the system? Does the internal thermostat need to be fixed? I thought they did it when the replaced the radiator in step 1 above. Could there randomly be a clog in the system ?