1. No, you are NOT legally or lawfully since you have YET to be approved for deferred action. This mean you can be deported. Chances of this are slim unless you mess up like commit a crime. Best suggestion is to keep doing what you have been doing these years and not mess it up for you.
2. Only if you have been approved and have your EAD/SSN/ some jobs require a DL
3. If you don't have any then you don't have any, dont lie or anything
4. I have no idea about that, I would think you should ask those who work in the retail stores. However, following trends, its easier to get hire for low skilled jobs than high skilled jobs.

And no, you are NOT eligble or even can apply for jobs at this time as you are missing your EAD with approval letter, and with out an EAD you cannot acquire your SSN and with out an EAD and SSN you cannot apply for jobs. Whats going to happened when you start to apply and oh snap I don't have my SSN yet..."well that sucks come back once you do, NEXT!"