Just because Ronaldo is losing, doesn't mean that he will join the winners, he may have done that before, but he switched leagues to do that and he deserved to be at the best teams. Like when he moved to United, then United was good, but United wanted him, and he was good enough to play there, or when he moved to Real Madrid, real was the best team, and he deserved to be there, and when he moved to Juvnetus, they were winning the title 10 years in a row, so he went to best team because he deserved it.
I don't really understand what you mean. However, Ronaldo always brings positive impacts to the team he ever joined. He has a good record/stats in Man United, Real Madrid, and Juventus. Sure, he only joined the team when the team really wants him. It is the same as when he decided to move to Al Nassr. Anyway, he always deserves to join any team. He is an experienced player, he also still has the ability to keep playing in a good form.
However, when we are talking about moving, he never went from same league to better team in same league. So if he ever leaves, I am sure that it would be for another league, but I believe he looks quite happy there and won't really change it at all, seems like he will be happy to be just there.
Indeed. Ronaldo never moved to another team in the same league. Ronaldo is a loyal player, he doesn't want to play in the rival. Recently, we heard a rumor that Ronaldo probably moves to Al Hilal. If we considers the history of Ronaldo's transfers, it is unlikely to happen. When Ronaldo leaves Al Nassr, he probably moves to another league. I guess he will return to the first league that he ever played as a professional player (Primeira league).