Do we need WhatsApp Personal or Business WhatsApp to start using WAGHL services?
You can connect using any, either personal WhatsApp or Business, but WhatsApp business is recommended.
Can I connect multiple WhatsApp numbers under a single GHL sub-location?
At a time, you can connect only one WhatsApp number, if you want to send from another number then you need to disconnect the 1st number and then you will be able to connect the 2nd number.