The possibility of early exercise is not valuable for call options on non-dividend paying stocks, so the value of the American call is the same as the value of the European call.
Yes. Only dividend paying stocks are called early.
i.e. - the early call is only valuable if there is a cash flow on the stock that you can invest. Otherwise, there is no advantage in exercising the option early (since you would lose the time value), hence it is the same as an european option
remember there are instances where puts should be exercised early though