Why it is booting in safe mode every time?

I bought my MacBook A1278 in 2014. It’s my first laptop (an investment to learn and code apps) and I thought it would serve me well considering it’s from APPLE.

I upgraded the memory (from stock 4 to 10 GB) to speed it up and started using it mostly on weekends and sometimes with a gap of 2 months. Eventually the screen started forming dead pixels on top right. I hooked it to an external monitor. After a few months, it refused to boot up normally. On resetting SMC and PRAM multiple times it used to work.

I suspected the keyboard and disabled shift key (thought it would have stuck somehow) using Karbinar Elements which did the trick! Past few months now, my System simply boots in safe mode. It ignores the Karbinar as well as, SMC & PRAM reset.

The local repair shops don’t guarantee how usable it will be after spending the service cost (almost half of the original purchase price). Also, new purchase is an expensive option and so called high end Macs are totally not worth, in my opinion.

So here I am seeking your advice. If there is anyone on this forum can help me resolving the issue(s), it would be highly appreciated.

I love the machine and it hurts me when I see it this way ); Help!

Battery info