Typically, running OBS as admin is a really bad security idea, but on such a low-end system, you are bound to have CPU and GPU contention issues, so running OBS as Admin will make sense for in your case
You have audio at 2 different refresh rates. pick one and make all the same
18:36:14.912: Video stopped, number of skipped frames due to encoding lag: 71545/125858 (56.8%)
I'm not knowledgeable enough to recommend a specific video encoder to use with your CPU/GPU combination (I use NVENC) that might help.
Until you get a better response
- Forget (remove) all the filters and effects. See if you can even get a stable stream without it. Then slowly add effects, while monitoring via Performance/Resource Monitor to make sure not maxing out CPU, GPU, RAM, disk I/O. I couldn't get a laptop i5-6500hq and GTX gaming laptop to reliably stream with a simple setup.
- if that doesn't help, drop your bitrate down to 1000 or something like that. Run a test stream, and check your log for message like what I posted above.
