Q: Engine takes too long to warm up runs poor until it warms up.

There is only two possible causes of an engine running colder than it is supposed to. The fan clutch may be locked up and would cause a load on the engine and excessive airflow across the radiator not allowing the engine to get to operating temperature fast enough. It may take a real long time to even get close to the normal operation temperature. The thermostat controls coolant flow through the engine and is suppose to stay closed until the engine starts warming up and then allows the coolant to flow through the motor at a controlled rate maintaining the correct engine temperature. If the thermostat is stuck in the open position or has been removed for some reason then the engine will not warm up very fast or may not have a constant temperature control of the engine. I recommend having the cooling system tested to see if the cooling fan clutch needs replaced or the thermostat is bad. You may have both problems and this would compound the problem causing the engine to run cold all the time and no heater performance. Have a mechanic like one from YourMechanic come to you and do a coolant performance test and determine the cause of running too cold and rough.