Final Exit from Bahrain after resignation

Someone helps me with my queries for final exit from Bahrain.

1.    My work visa company will cancel post my resignation and final exit from Bahrain, but my CPR & Driving License remain active. Can I enter in Bahrain again on visit visa from India and spend some time in Bahrain?
2.    What formalities to be done with Grade/Class 3 student TC? Is it required to do attestation from Ministry of education and then from Indian Embassy? What sort of problem may I face in India for admission in Grade/Class 3 CBSE board school, if TC attestation not done?
3.    What to do with Standard charted bank credit card? I want to keep this card to be active for next 3 months to utilize my rewards points. Is it compulsory to close credit card and bank saving account?
4.    Are there any formalities required at LMRA and something to be done for visa related things from my end?
5.    How long my prepaid STC mobile remains valid post final exit from Bahrain.
6.    After 6 Months need to join same company in Bahrain then what should be the formalities for work visa, hope it may be same as per new work visa only.

Thanks in advance and sorry for some of the queries not clearly asked.