You need to dilute or change the water only when one or both of those levels exceed desired levels. There is no regular schedule for this, as the levels and their increase rate will vary from pool to pool. Get reliable test equipment and test the water yourself periodically, or take a fresh sample of water in to your local pool store to have the levels checked.
Dilution. You would need to drain and replace some of the water in the pool.
the water pump is probably no longer working. Gravity will drain most of the water, but the water pump pumps out the remaining water. You might need to replace the water pump.
According to DIY on Hot Water Promblems if theres not enough water then you hit the reset button. If the water is too hot then change the temperature and reset. If you have a leaky heater then you need to replace the valve. If you have a rusty tank then you need to replace the water heater. If you have a noisy heater then you need to drain and flush the tank. If you have dirty water then drain and flush the tank and do it on a regular basis.
Yes you do.
If its too high you have to dump water and replace it with fresh water be carefull to work out how much water you need to replace you wouldn't want to have to do it again. If the pool drain goes into the public sewers ensure there are no local rules affecting such discharge, or that you have the necessary consent.
To get water to it, and to have it drain
Most residential HVAC systems do not use water, at all.
depending on how it got water in it, then yes or no. if someone put water in it, then drain it and refill with tranny fluid. if it has some sort of leak that allows water in it, then further repair is necessary. chances are if you have water in your tranny then you have probably destroyed it
Sounds like you need to replace the oil pan to fix the situation.
you need to know the PITCH of the drain line to give an proper answer
NO
The only thing you need to do is put the motor in the verticle position when you take it out of the water. The water will drain out. Yes, even the water that is in the "water pump" will drain. DON'T DRAG YOUR LOWER UNIT ON THE GROUND.