Ktoyou,
I haven't been posting because my health issues have been pretty bad lately, but I read this and couldn't help but reply.
I was a HVAC/R service technician for 20 years, and a very good heat pump technician. It was one of my specialties.
Depending on what kind of thermostat you have--digital or electro-mechanical--your thermostat issues may not be anything more than your thermostat being out of level, for the electro-mechanical tstats use a mercury switch attached to coiled bi-metal spring that expands and contracts with temperature changes, and that movement causes the mercury to move to either open or close the connection between two wires. And, if the thermostat is not exactly level the relationship between the thermostat setting and the temperature sensed will not be correct. Digital thermostats are not affected by being out of level.
I don't think whoever you called did you any favors, at least not according to what you have posted here. If the tech did not repair the leak this is an ongoing problem for you as the refrigerant will simply leak out again. Anyone who charges a system without locating and repairing the leak is not dealing with you fairly.
Also, going on the assumption that the leak, if a leak truly exists, was not repaired but the tech just added refrigerant, his skill level is suspect. That means there could be a number of issues at stake here that could cause your heat pump to not put out it's normal level of heat. The reversing valve, the valve that switches the flow of refrigerant between heating and cooling could be leaking so that the heat pump will not operate correctly in either cooling or heating as hot gas, i.e. hot refrigerant gas coming directly from the compressor, will be bypassing the route it needs to take to heat your house. Or, you could have a partially plugged coil in either the indoor coil or the outdoor coil. Or, you could have a compressor in which the valves are worn out so that the system becomes very ineffecient. There are a number of issues that will cause a major reduction in heat pump efficiency and all too often low-skilled techs will blame a leak not knowing where to look for the real underlying issue.
One thing you might try is to set your thermostat to the Em. Heat setting. This will cause the indoor fan to run only when the back up heat runs. It locks out the refrigeration system and keeps the system from blowing room air temperature which, due to the wind chill factor seems colder than it actually is, and will cause the electric heat to come on at the normal temperature setting, not 3-4 degrees colder than the normal setting.
The other thing to understand is that a heat pump heats by moving a high volume of warm air--approximately 30 degrees above room air temperature--so that under normal operation a heat pump will put out about 100-110 degree air in a 70 degree home. This "feels" cool because of the wind chill effect of moving air.
I would also advise you to NOT install a furnace larger than what is needed in your climate. Do this shortens the heat cycles so that your comfort is reduced because the furnace will constantly cycle off and on because of the extra heating capacity. That results in a very uneven temperature in your home. The temperature will rise quickly and then cool, rise quickly, then cool. Meaning that the temperature in your home will constantly be rising and falling. A correctly designed heating system will not do that. It tends to lesson the spikes of temperature increases and falls.
If you do move, and need the temperature to be around 80 rather than 70 talk to a reputable HVAC dealer and tell them you need it designed for an 80 degree indoor temperature, or whatever your needs are. Normal design is a 70 degree indoor temperature for heating and cooling. A good dealer will do that for you and can do it very easily with their system design software. If they don't have that, then I would stay clear of that dealer and find one that actually designs comfort systems for the home.
Lastly, it is not a very easy thing to find honest dealers and techs. Research anyone you call out either for design and installation or repair. See how many customer complaints there are about them. In 20 years of service work I found exactly 3 honest business owners in the HVAC and refrigeration field. They are very rare. There are undoubtedly more than I found in my working life in 3 states, but a consumer has to be extremely careful in selecting one for dishonesty seems to be the norm.