No. At 6, the male body is not developed enough to produce sperm.
You can ejaculate 2-3 times a day, every day with no problem. Your body will keep producing sperm for practically your whole life, well into your 70's and probably longer.
Yes and entirely natural.
you call a 16 year old girl a 16 year old girl
When they go through puberty, which is different for everyone. For some it can be around 11 or 12, but for others it is not until around 16
it depends on if its a 16 year old boy or 16 year old girl
Not without the permission of the parents of the 16 year old.
The 16 year old has to have parental consent.
No
it is not illegal for a 16 year old and a twenty year old to be together in England
Probably the 16 year old, depending on how much he/she has learned. The 5 year old may be more intelligent, or notices things the 16 year old doesn't though. Remember, the 16 year old has had 11 more years to learn.
It is illegal for a 16 year old to date a 28 year old man!