Late reply but hopefully this will help others.
1. Question: Would you recommend to remove it and clean underneath or is there a simpler way to clean the keyboard from the insides?
Don’t do it. I have removed and cleaned the spacebar on my 2016. It’s near impossible to *not* break the fragile pins on the butterfly mechanism. If you do proceed, here’s my experience.
The spacebar has four clips and four hooks. Four clips at the top of the space bar will pop off easily with a guitar pick using near-zero force. The four hooks at the bottom will break if you apply any vertical force. I managed to detach my spacebar without breaking any hooks or clips. However the process doesn’t end there.
Below the spacebar is a white clip aka the butterfly mechanism. The white clip has the world’s most fragile pins. The pins are held in place by three clear plastic holders. The middle holder also has a metal dome that activates the switch. Beneath all three holders are tiny LEDs on the case itself. The LEDs are fragile and exposed, so be careful.
To remove the white clip you first need to remove all three holders. The three holders are glued in place and once removed they have to be cleaned thoroughly and new glue applied. Use a guitar pick and gently run around each clear plastic holder. Do not pull or put any leverage on the clear plastic holders or it will bend and break. Once the holders are removed the white clip comes away freely.
If you attempt to simply remove the white clip without first removing the clear holders you will break its fragile pins. When removing the space bar if you push the guitar pick in too far it will accidentally catch the white clip and again break the pins. And if you try and reattach the white clip without first removing the clear holders, you will also break the pins.
So I managed to break 3 of the 8 pins because my guitar pick caught the white clip and I applied too much force, lifting the whole thing rather than just the space bar. That said, I found the most amazing amount of dirt, hair and junk beneath the white clip. If you’re going this far you might as well keep going and clean the whole thing. I used isopropyl and a cotton bud. This also removed the glue residue.
For reassembly the white clip has metal rods which face downwards. Around the rods are eight holes for the clips/hooks of the space bar. The four holes at the top are symmetric to take the clips. The four holes at the bottom take the hooks; they have a smaller space near the trackpad and a larger space up north. Place the white clip down first - it will be loose - and then glue the three plastic holders on top to hold it in place. I used a glue stick and it seems to be held on well enough. Then reattach the spacebar by first inserting it at an angle to catch the four bottom hooks, then press gently along the top to catch the top clips.
After carefully cleaning everything and reassembly the mechanism works about as well as it did before. Which isn’t saying much because this is the world’s worst laptop keyboard IMO.