If it does blow just not cold air you should see if it needs to be recharged
No water, if you drive and don't fix, the head gasket WILL blow! Don't ignore it.
An air conditioner blows out heat
Replace your cabin air filter.
you just move the flaps around
You have a vacuum source at the intake manifold that is possibly disconnected.
no but it may depend on the conditioner
Portable air conditioner will not blow cold air. What to do?
Not likely
yes, however, if the ac does not work then you will be unable to blow cold air on a hot steamy windshield to defog it.
about 5 minutes
It's out of freon or refrigerant.
Max