Good morning, Sjoizjuk.
(1) We recently had a thread about stative verbs & the progressive.
(2) Hopefully, another member will give you the link. (I don't know
(3) Very briefly:
(a) Everyone agrees that "I want a car" is "good" English.
(b) Some people accept "The busses are getting so crowded and slow that my friends and I are wanting a car more and more every day."
Some native speakers are horrified by such a sentence.
(c) Many (most?) native speakers seem to accept "I have been wanting
to buy a car for a long time. This seems the perfect time to do so."
Have a nice day!