So, even if I enable cross save and transfer my Bnet account over thus erasing my titan, I won't be able to get him back through a cross save import from another platform?

You stated in your original post that your only character was on Steam, so there would be no reason to transfer characters because you are already set. Don't know why, or how, you "recently" bought a Battlenet CD key when the game moved to Steam back in October. That key has been useless for six months.

I bought it a while ago and never played it (my how time can fly when you have obligations!). I recently started playing on Steam and have made a considerable amount of progress. I am now realizing that one must either re-purchase the game on steam in order to utilize the material that I have already paid for, OR, coerce a non-existent staffing member from bungee to create a requisition, write a job description, and get a position filled for a person with the appropriate knowledge and access to fulfill my request that has been overlooked for 3 months.

Destiny 2 is free. There are two DLCs (Forsaken & Shadowkeep) that must be purchased for any and all platforms you play the game on.

I'm aware. Forsaken was purchased on battle.net a while back and never transferred to steam because I never played the game. When I started a new character I did not transfer the DLC from blizzard and I am therefore attempting to transfer the DLC over without losing my Destiny 2 character on steam.