Yes, I think so. Very effective. Check pic
Yes. Have pic with only minoxidil few pages back. And you can definetly see difference. At that time I was applying just minoxdil on topp, but in front I was doing also dermarolling. And difference is huge! Scroll back few pages and you will see pic I'm talking about.
I use dermaroller for better absorption of minoxidil. But I know that some users who only dermaroller for collogen production. I have not tried it so I do not know if it works. Other thing is that from youtube I have seen that some combin oils and Dermaroller with good results. I have not tried it.