Your system sounds very much like software issues and I would say you are a prime candidate for a reinstall. Who puts up with those issues on an ongoing basis?
Like most here, I've been using ad blockers for many years and I'm still amazed at how much faster sites load when you block the additional crap. Depending on the site, sometimes up to 5-10 times faster - mind you, the important stuff does load first. Lazy loading (what a lame term) will be insignificant compared to ad blocking tech.
The way I see it, it's a glorified Chromebook at an inflated price. You kinda get what you're paying for here. It's not like it goes head to head with the rest of the Mac laptop line. No expandability, USB 2 only, no touch ID, slow charging, It really is a cheap notebook.