Bangle JS 2 bought less then a month ago started acting up

Actually yes, I should add that with the backlight on, the screen does have slight lighter/darker patches right at the bottom which are slightly visible when there's an area of flat color at the bottom of the screen.

All the watches do it (it's a side effect of the transflective screen being hard to backlight) and yours would have done it from the factory - but maybe you only just noticed it?

I had pixel artifacts that I couldn't get on camera in time, some vertical lines in the widget areas

If it's just within the widget area then that's almost certainly software - a badly behaved widget.

If you've been playing around installing loads of stuff (which is sounds like you might have!) then there is a definite possibility that some of that software is misbehaving and causing problems.

As @fanoush says doing a Factory Reset should definitely be your first port of call, as code that's taking too long to execute could easily be pausing the device for seconds and making the touchscreen appear unresponsive