Depends on the amperage of the charger. A 10 amp charger will charge it in about 1 hour.
Yes, as long as you do not overcharge it.
Yes as long as it is the right voltage: a 6v battery needs a 6v charger; a 12v battery needs a 12v charger. <><><> If you can set the battery charger's output to give either a 6 or a 12 volt output, then you must always remember to set it to 6 volts if you want to use it to charge a 6 volt motorcycle car battery.
In 24 hours it will be charged enough to start the car. You really need a much larger charger for a car battery.
If it is an automatic charger let it charge until the charger shuts off.
A trickle charger is a car battery charger that is designed to be left on a car for very long periods of time to re-charge that car battery by slowly adding charge to the battery.
You do not charge a 7.2 volt battery with a 9.6 volt charger period unless you want to ruin the battery. You charge it with a 7.2 volt charger.
I doubt the charger is putting out 30 Amps on a slow charge. need more info on battery and charger.
With a charger specifically designed to charge this battery.
As long as both batteries are the same voltage, you can jump start with the battery. If you want to charge the battery then use a battery charger.
As long as it is a 12 volt battery you can if you set the charger on low.
A .6 amp charger is a trickle charger. It would take days to charge a dead 12 volt battery with this charger. You need a 10 amp charger which will charge it in a couple of hours.
Depends how flat it is and the capacity of the charger and also capacity of the battery. A 6 volt battery fully charged should read about 6.5 to 7 volts when fully charged.