First Design (Stereo 500 Series DI)

[CSmotherman2715]

Hello! I'm hoping that maybe someone can check my work and make sure I'm not doing something silly/wrong. I'm beginning to grow from the hand-holding approach of DIYRE/CAPI and want to create something that I can't find in existence - a 2 channel DI that occupies a single 500 Series slot. The front panel will be made from a modified blank, and a coupler will allow the XLR Input on the back to be the second output. Inside, I'm planning on using a Pikatron UP3096M, the same available in the CAPI VP312DI and wiring a fairly simple DI with nothing but a ground lift. I've diagrammed this out below.

The things I've trying to be sure of:

1. Have I read the transformer diagram correctly and therefore wired things correctly?
2. Is Pin 1 indeed the audio ground, and can all audio grounds be tied together like this?
3. Being a passive circuit, is there any reason for an electrical ground?
4. Do I understand the 500 Series Pinout Correctly?

If anyone is able to clarify help me be certain I'm approaching this correctly, that would be amazing. Thank you!

This is my first post so if I posted this in the wrong place or need to provide more info, please let me know.