No, as the term Ad-Hoc implies this needs to be done as required or on a monthly basis.

MTN Business does not do URL filtering by default, however there are 3rd Party solutions that can be recommended for this purpose.

No, only one recurring bundle can be applied to an APN, you can however add a single Ad-Hoc bundle per billing cycle.

Yes.  In order to deploy MTN Managed IP PBX, clients need an existing MTN Business Access service such as MTN Internet Dedicated, MTN MPLS-VPN or certain of the MTN Remote Access services.