My e-file training was part of my enhancement training. In fact, that's how I did my filing on my models while practising. It was under very close supervision though and because I had one-on-one private training, Deb watched every move I made. She'd show me on a couple fingers and then I would give it a go. Honestly, I never felt nervous with it and I think that plays a big role. If you don't feel confident, you're much more likely to do some damage. Also, you would always keep your file at a very low speed when you're first learning. And, never use a carbide bit at first. Get used to using a sanding band and once you feel comfortable with that, you can graduate to carbide. I actually rarely use my carbide bit as I prefer the sanding band. I only use it when someone has MMA on their nails I need to remove.
It's true you don't need to use a file to create beautiful nails but I really feel it's faster in the long run when it comes to doing rebalances. The only time I use one on a new set is to ensure my final shape is as flawless and as smooth as I can get it...and I find the e-file helps me achieve this. And when it comes to removal, it's MUCH faster considering most gels are not soak-off.