As for Roll, I don't want to enter the debate on what constitutes cheating, but from a game design point of view, if you give players a feature, like a Re-roll button, you should expect that players will use it. As far as tabletop is concerned, I think the Roll rule for Ability Scores is simply bad design, but it's also one of DnD's sacred cows and is still the default rule in 5E.
Which seems so bizarre to me. Standard Array is SO CLEAN, easily my favorite way to go with the default racial attribute increases.