HP Z1 G1 AIO Workstation upgrades?

[Alpine_B]

Hello, quick question for the pros. 

I just came across an HP Z1 AIO Workstation, first generation (G1). It is equipped with the Xeon 1245 v2, a HDD, 8GB of RAM, and the nVidia Quadro 1000m. 

I know these are ancient Sandy/Ivy Bridge rigs, but It is in flawless condition, and I paid $100 USD. The appeal is due to the workstation being built like a brick, ease of upgrades, having a 27" 1440p IPS display, and being compatible with some old parts I have lying around. On top of that, I am a big fan of HP Enterprise gear, and enjoy when my IT guys quote me $1,800 USD for a basic office PC and I spend $200 USD on something that posts higher benchmarks.

I'd like to irresponsibly upgrade this machine. It'll be a workstation for office use, and I'd like it to be able to do some basic gaming (Hades, Northgard, Dark Souls Remastered, ect), as well as some light video/photo editing work. 

I have 2x 2.5" SSDs, mini-PCie wifi/bluetooth cards, mini-PCIe to NVMe adapter, 2230 NVMe, 32GB of RAM (4x8GB), some mini-PCIe wifi and mSATA cards, and a few MXM cards. (Some AMD Radeon Pro WX 4150 and 3200s,  Quadro m2000m, Quadro p3000m, a GTX 1060m, and a Tesla m6, with the vBIOS flashed to a GTX 980m. 

I will be back at my office from a work trip in a few days, and wondered where to start?

I am not sure if a CPU upgrade is worth pursuing? The E3-1280 V2's are ~$40-50 USD, but I have a 3770 sitting in the closet if it makes sense to swap.

With the mini-PCIe to NVMe, I would use the internal USB header and use Clover or Duet for the NVMe to boot a UEFI OS, right?

I read that the GTX 980m is compatible, and saw that there is a 'UserBenchmark" rating with a 980m. However, I read that the Z1 G1 has a LVDS display connection, while the G2 has an eDP display connection. (The 'UserBecnhmark" on the G2 shows a GTX 1070m benched). 

Will the Z1 G1 support Pascal-based architecture, even with a LVDS display and pascal requiring eDP? Doesn't the GTX 980m only support eDP as well?

(Is this bypassed with "graphics switching" or nVidia Optimus, where the iGPu on the CPU is outputting to the display panel, and the MXM GPU is doing the processing?)

As always, I appreciate everyone's time and expertise in these matters. Have a fantastic day, and stay awesome out there!