Is it normal to never have a heavy period? I only have light ones, and they r never regular... Normal?

Probably. The amount of menstrual flow varies from woman to woman. It is normal for some women to have a light flow and for others to have a heavier flow (within limits). If your cycles are also irregular, then this can be caused by problems with ovulation. If your cycles are between 23 and 42 days, then it is probably normal. If they are closer or farther apart, discuss with your gynecologist.
Sure. Every woman is different. Your cycles might be dependent on your body build - slight women can have slightly lower estrogen levels, making periods lighter and more erratic. As long as you are menstruating, you should be ok. Of course, make sure you discuss this with your primary physician.
Possibly. The amount of bleeding each month is variable, and the perception of the amount of bleeding is variable. It is not abnormal for you to perceive your periods as "never heavy". It is not normal to "never be regular". Most women have periods on average once a month, and they may not necessarily start and end on the same day each month. If yours are more or less frequent - see your doctor.
Light periods. Both heavy and light periods may be considered not normal in most situations especially if they are very irregular. If your periods are out of the norm, you might have some degree of hormonal imbalance and may need to be addressed accordingly to avoid future complications.