yes
I'm not so sure :(
No. A loose battery connector will cause problems drawing power from the battery to start the vehicle, and it may present a bit of a problem charging it (but that is not likely because the charging current is low compared to the starting current). If you have a loose connector and the battery goes dead, clean and tighten your battery terminals and start making some checks. The loose connector will not cause your battery to go dead.
On some car yes it will.
A weak battery, loose/broken wires making a short, defective sensors that monitor what the gauges are displaying
== == A low battery in the key fob will cause the fob to loose it's function, not it's program. A low vehicle battery will not cause this problem.
Certainly, a loose wire on the car battery can cause the car not to start.
No, the alternator will not charge the battery with the negative terminal loose.
A loose battery cable can cause your vehicle to on most stall and it can cause the lights to Flickr. Make sure your battery cables are tight and free of corrosion.
Sounds like the alternator has failed and you ran the vehicle until the battery was drained.
No, the battery has nothing whatsoever to do with the belt other than the belt is driving the alternator which recharges the battery. The alternator is working hard to recharge a weak battery. If the belt is squealing then the belt is either worn out or it is loose. If it is loose it is because the tensioner is defective and not holding the proper tension.
Cause a no start situation.
A loose battery terminal will cause intermittent power supply, high resistance and heating. A high resistance will cause a voltage drop, as more current is drawn from it.