It is recommended to have as few capture sources in the same scene collection, as they will interfere with each other so simply create separate scenes, one for display capture and the other for game capture, in your case.
You can save a bit of space by recording audio at 160 bitrate and/or increasing the CQP value. Huge filesizes are expected due to the resolution and frame rate chosen. Most people record at such large filesizes then reencode it to their preferred settings.
Outside of OBS, you could try setting power management to "Max performance", in your NVIDIA control panel then doing the same with Windows 10 power plan.
Other than that, your log isn't really showing any issues recording. The only judder that might be visible is due to either the graphics card not being able to maintain consistent ingame FPS at 60 or 120FPS, thus causing OBS to duplicate frames or, if you watch your own recordings at 60FPS in your 144Hz monitor, because 144 doesn't divide evenly into 60, you will see judder that isn't actually in the recorded video.
As for the SSD comment, it's incredibly hard to wear out enough cells in a modern SSD to the point of failure, as long as you leave around 10-15% free space for all wear-leveling solutions to extend its lifespan, even if you write large amounts of gigabytes of data every single day. Assuming each cell can change its state 3000x (worst quality scenario), it'll still require a mammoth amount of data to be written. In every single case I've seen of SSD failure, the controller failed or lack of free space led to excessive wear. The former was just a quality control issue while the latter is the most common user error. As long as you buy from a reputable brand, you'll be fine.
I'll update this post if I remember something else.
