I think having this as a real combat job would be preferable.

Melee dps using... dunno, a quarterstaff maybe, while sharing, dunno Rogue/ninja gear maybe? Looks workable.

I don't see the appeal of having that job taming special mount tho. We already has plenty for everyone,

For the tamable beasts, theycould be of various families where each beast family have a define role/skills/toolset. Specific beast within a family would be more for personal preferences/glam/look.

Besides basic combat skills, each family could provide some buffs (personal or group) associated with the beast family role.

They could also have one long recast strong skill or something in the same vein.

That pretty much sums up my views on what this job could be.