Something is definitely wrong there. You should not have to use temps that high for PLA? I use 50 or 60 for the HBP on my Prusa 13, my son uses 40. We use 3mm extruders on our Prusas but I have never had to go above 220 degrees. Are you sure your thermistor are set in all the way in your hot end? I might try and get a real temp reading with a laser thermometer? I print right on blue painters tape all day long? Wipe with alcohol if you want it to REALLY stick. Curling of the filament might mean you have dirt in the nozzle? Try cleaning that out.