Question about Mid 2010 Mini

I picked up a used Mini, Mid 2010, 4GB Ram, 320 GB HDD and 256GB Nvidia Graphics, and a Intel Core 2 Duo processor

The last supported macOS for this machine is Bug Sur. I have upgraded the SSD to a 256GB for now.

I have a couple of questions which I’d be grateful if someone can help me

1. OLCP a good idea, for this? This Mac doesn’t have Metal enabled graphics. If this is the way to go, please suggest which version I should go for? Big Sur works surprisingly well, even with just 4GB RAM. My only concern is lack of modern web browser! If I could somehow get the latest browser (any) working I would not mind staying on Big Sur
2. Is 16GB Ram worth it for this machine? I was also curious if a 4+8GB configuration would work or not? If anyone is using this config please let me know if it works?
3. I’d like to know what are you guys using the old Mac for?
4. In the image, is there something wrong in the highlighted area? I noticed this when upgrading the SSD. Pretty sure I did not do that.

As to why I’m asking here rather than in the Mac community, I believer people here have experienced both worlds and should be in a better position to answer.

Thanks