Have you used compressed air on your keyboard? I've had a 2016 model get sticky/repeating/not pushing keys repeatedly and the air has always brought the keyboard back to 100%.
And I'm sure the constant pressure is putting more strain on the computer, I don't believe its causing the keyboard issues though. I use my 2015 MBP for encoding, the 2.8 i7 will run at maximum for 24+ hours sometimes. In 2018 the motherboard, both fans and screen failed. All repaired under AppleCare, I highly doubt all those components would have failed if I was just using the computer to surf the internet and write emails, but I got the computer to perform, if I don't use it what's the point?