score:4
If you are relying on your father's sponsorship to get an entry clearance for your PLAB, you should get the most recent 3 - 6 months of his bank statements. These should be accompanied by a letter prepared by your father that explains each and every movement through the account and establishes the provenance of his funds. Provenance of funds is a very popular refusal reason at the moment.
Your evidence (including your father's explanation) should be translated.
If you want to play it strictly by the book, the bank statements should be originals provided by the bank or taken to the bank and be authenticated as genuine by the cognizant bank officer.
For your other question, they already know that PLAB applicants are just starting out in life and may not have impressive employment credentials. You can compensate for this by demonstrating that you have great offers on the table or something else that shows promise.