Real Madrid will be a top priority for Mbappe, that is if Real Madrid still intends to get him, because I don't know whether Real Madrid has made a special approach to Mbappe or not, and what is spreading now is just a rumor that says Real Madrid still really wants Mbappe to be part of their squad.
If the situation remains the same, it will be a great missed opportunity if Mbappe returns to doing things like last season where he chose another team than the team that has actually been his dream since childhood.
As far as I know, Florentino Pérez is still interested and has a plan to sign Mbappe. But he stated Real Madrid possibly sign Mbappe next year. We all know that Mbappe's price is very expensive, Real Madrid is waiting for Mbappe's price a bit lower. Mbappe also has confirmed that he wants to stay in PSG this season. However, if it is possible, Real Madrid may sign him this year because Real Madrid is urgent to have a new striker. We don't know what to happen in the next few weeks, Mbappe may change his mind and decide to leave PSG sooner. Let's see where Mbappe plays this year!If the situation remains the same, it will be a great missed opportunity if Mbappe returns to doing things like last season where he chose another team than the team that has actually been his dream since childhood.
Check this: https://onefootball.com/en/news/florentino-perez-real-madrid-want-to-sign-kylian-mbappe-37651815
I still feel that this will only return to a strategy where indeed all planning must be made and as you said Mbappe's current price is too over but it is indeed difficult to reduce it because with the performance that he always emphasizes and is still above the average Mbappe's value seems to be still will continue to rise.
I don't know, I don't have any impression of this coach because to be honest I didn't even have any expectations apart from that in the media it was hyped up that he was Ronaldo's former coach because indeed this might be one of the conditions where it will increase reader traffic 
Now he will be at the helm of Napoli next season, hopefully he can make the expectations of Napoli fans come true, at least to continue to be able to compete in the Scudetto hunt.
What you have to think about now is the players, how strong Napoli are holding their players.
He is not well known except for the news about his dismissal from Al Nassr, but he has quite good experience in Ligue 1 as Lilie's manager by winning the Ligue 1 season 2010-201 and also the French Cup in the same season and also experience coaching in Marseille and Lyon, but at AS Roma he was not so successful even though he had a better winning percentage than when he was still in Ligue 1. It is quite natural that he is doubted because he does not have a record of success in European competition, maybe Napoli saw something we couldn't see SourceNow he will be at the helm of Napoli next season, hopefully he can make the expectations of Napoli fans come true, at least to continue to be able to compete in the Scudetto hunt.
What you have to think about now is the players, how strong Napoli are holding their players.
Replacing Spalletti with the majesty and consistency he performed so superbly last season was more or less a burden of course. He must try to do the same scheme as Spalletti did, only of course such a thing is not an easy matter. Moreover, we also know that it is likely that other big teams are now starting to have the desire to overtake him at the top and get rid of Napoli, who is now the defending champion.Despite his fine form in Ligue 1 a decade or so ago it has been too long and indeed the hope is he is not blunted tactically for a big club now.