How far from the house should the outside unit be located?

If your outdoor fan is a vertical discharge in other words if the fan blows the air up from the top of the unit then one foot from house is fine, but if it is horizontal discharge or blows it out the side then the airflow needs to be directed away from the house or the unit needs to be moved away from the house far enough that it doesn’t restrict the airflow.
For the blower running on high speed a 4 ton unit is usually 1600 cfm so on low cfm it may seem like high speed. There should be some speed taps on the indoor pc board and if you look in your installation guide it should tell you what taps you need to get the lower airflow if its not correct.
For the luke warm air in the 2 ton mode, the coil is a still 4 tons but the compressor now is only pumping 2 tons of refrigerant so the discharge temperature and head pressure will be much lower and that is what determines how much heat you get, so you will get less heat. The 2 ton mode is for times when you only need a little heat or cool, when you need more then you will get the 2nd stage which is the full 4 tons of heat.