I do that when I'm not racing, i.e. exploring the track or just messing around, as you said specially on some cars it doesn't feel right when you flat shift. But when I'm racing I know that it's faster to do it and I just do it.
My mum didn't trust it either and I had to ask my uncle, which has got a PayPal account, to buy it for me. It is safe indeed, I know lots of people who work with it pretty often and never had any PayPal-related problems.
Talking about bugs, don't know if it's reported/solved already of it's even a bug, but I don't get any ''clear all objects'' button in the layout editor, and it's bugging if you have a big layout and want to load the regular track.