4
They are two completely different jobs. A developer write SQL code for the different applications. A DBA handles the database to make sure it is optimized and the data can be restored in the event of a catastrophe. "Better" depends on what problem you are trying to solve.
4 Its depends Upon interest if You are Good in Db Queries Choose SQL Developer else Choose DBA
4
The job of the Database developer is to create the platform for the organization's database whereas the DBA manages the platform for the organization.
It's just like a contractor(database developer), He is being paid to build a house whereas the landlord(the DBA) maintains the house by ensuring correct practices so that the house can last for a long period of time.