I was also an iTunes user for over 10 years and I too miss the vertical scrolling, the Roon team have said that this feature is on the road map, I know that doesn’t help you now but if you are willing to spend the time with Roon it will get easier, please don’t give up.
In the words of the great master Yoda, “You must unlearn what you have learned” 
This is a downloadable PDF which I believe was maintained by a Roon user, I don’t know how up to date it is: https://1crm.com/docs/Roon_User_Guide.pdf
This video is also very helpful: Can we have a Manual please? [User Guide Is Live!]?