Cosmetic Customization: The idea of cosmetic customization is great and definitely should be implemented. An issue is that some of the cosmetic changes are difficult to see/notice.

Progression Customization: I am not a fan of progress customization in this game. People who have upgraded gear etc that outclass new players at least on paper is a deeply unsatisfying prospect for the style of game this is. Overwatch shows that progress customization is not needed to make a game enjoyable. I will not buy this game if stat advantage goes to those who have payed or played more than others.

Resolution: I do like the idea of stat alteration if it can be implemented in a good way, however base stats for the characters seems like the most efficient way to keep the game balanced and fun. If stat alteration does stay in the game then game balance will more difficult monitor but monitoring it will need to be done. Also, as I said if progression customization stays in the game I won't be buying it, however if you are free to make stat alterations as desired from the beginning then I won't have an issue as long as balance is closely monitored and adjusted as time goes on.