Both BSM and GSM can benefit from Smelting and Nailcasting
Personally I would use
First points on BSM for Smelting (helps both with turning ore to nuggets, which you need a lot of)
First Points on GSM for Inlaying (helps with a lot of the Leves which means more chance at guild marks)
Beyond that Nailcasting is good for a few grind recipes and after that have a look at recipe you may want to grind on and buy books appropriately.
FFXIV : Khaap Keha : THM(Bodhum) In progress and enjoying it so far.
FFXI : Khaap : 75BLM, 75NIN Retired (sadly and it was purely down to graphics)