Can Inherited Roth IRA merged with existing Roth IRA?

No, the inherited funds (beneficiary IRA) have to remain in inherited (beneficiary) form. So the account/funds can only be distributed out of the beneficary IRA as a distribution or transfer to...

Maybe contact the bank you created the account with. Why you would try to ask this question here is silly.

An IRA is an individual retirement Account. A Roth IRA is just a type of IRA. Traditional is another kind.

Yes, this can be done. Typically, the account-owner simply opens a new Roth account and requests the custodian to move the funds at the request of the traditional IRA owner. Penalties will generally...

No, unless it's a divorce or death issue.