I took me 8 hours, but I finally finished building no my MK4 and did a few prints

I understand not enjoying the kit build process but I do want to encourage anyone considering buying a printer to get the kit. No matter what printer you get eventually you will have a problem and need to take it apart to figure out why, or to replace a part. And having that experience of building it will help so much with your confidence to fix it.

I feel ya. Assembly is a pain, especially for anyone with more advanced skills. The only reason I want to do my own assemblies is because I can easily clean and grease all of my bearings with a known product I will always have access to in the future.

I wouldn't use power tools with this kind of assembly. Maybe a high end electric screwdriver that will not apply a final torque, even then, raising the temperature of fasteners from friction makes bad days with printed parts. Spinning a fastener, like a pocketed nut, is an easy mistake to make and it really sucks to deal with it after it happens.

The one tip I try to tell everyone I can is to get a set of hex drivers like the cheap Bondhaus drivers set you'll find in the USA for ~$25. Using L keys for assembling a printer is nonsense. Just using a simple screwdriver handle makes an enormous difference. It takes away the tediousness.

I'm part way into my MK4's X axis. I also have an MK3s that I built from kit. I like know each and every part of my printer. That way I know what's where when I need to service it or fix my screw ups.