Welcome to the forum turps

Most people have lucids as a way to escape form nightmares when they are younger.

With your questions:

1) Your dreams will become less blurry over time especially with a DJ. They will stay blurry and unrealistic if your sleep patterns stay bad though.
2) BY using a DJ your dreams should become more realistic.

3) It depends on how vivd your lucid is in the dream. My first few lucids were blurry and dull with little control but after the first few they got more realistic and vivid.

4) Same with question 3.

Hope this helps