On age counter(s) 「歳 、才 / 年齢 、 年令」

Question

disclaimer: this question regards only the age counter for humans. For age counters regarding innanimate things(such as how old are cars or trees) please refer to this thread: General expression for the age of something

It's clear to me that 才 can be used as "slang" and it's mainly used by 小学生 (elementary students) so they'll consentrate on learning other "more important" kanji before reaching the level necessary for 歳 (JLPTN 2).

• 22歳です = 22才です
  Both of these "sentences" are equivalent, except only by the "formality" or "level" of kanji knowledge/usage.

But my question is regarding specifically 「年齢　、 年令」(both equivalent except for the level of kanji).

In what context are these expresions used?
Is saying 私は22年齢　considered correct?
How are they different from the first two?
Can someone give examples?

Answer 1

年齢 is not a counter. It corresponds to the concept of “age”. I believe you are sometimes asked to fill in your age, alongside your name, in certain forms. You are asked to fill in your 年齢. So (*) 私は22年齢 is incorrect. You can say 私の年齢は22歳です, although it sounds a bit redundant.

[歳]{とし} or [年]{とし} is also used for one's age. 年齢 sounds more formal.

I wouldn’t say 才 is mainly used by elementary students. It is widely used instead of 歳 as a sign of sorts to save strokes.

I don’t see 年令 very often.