Need help with PSN and multiple SE accounts.

Here is my current setup and situation.

I have my FFXIV legacy account that I've had since...well V1.0. On that account is...

• FFXIV for PC
• FFXIV for PS3

That SE account is linked with PSN A. PSN A is a sub account of PSN B...I use PSN B as my primary way to play with friends. (The sub account is old and the reason I had to switch is because to use the PS4 stuff, you can't have a sub account...it was created in error back when I was trying to rename my PSN)

Fast forward to today.
I need to find a way to get PSN B attached to the Square Enix account / Service account. I've read that you can have multiple FFXIV accounts linked to 1 SE account. Is it possible to create a new FFXIV account, link it with PSN B, then link that new account to an entirely new SE account?

I have an unopened copy of the PS4 copy of FFXIV right here, so I can assign it to PSN B at any time if that is the issue. Once I install it and go to login like normal though, will it tell me that I can't due to it being linked to PSN A?