Huf bank a/c operation post demise of karta

Yes to both.

Give a declaration  as new Karta being yourself.

This is the practical difficulty with few banks, for HUF account/s.

The bank should not have accepted the HUF deed when you were not presentable, though your name existed in original deed. Now they will not change their stand based on the declaration given to them by your father, as that opens up their mistake. That is understandable.

But with fresh approach with revised HUF deed as on date being you as new Karta, you will be able to open the account, though many banks hesitate to such formality, specifically private banks; but one out in five nationalized banks would entertain that.