My thoughts:
Attack:
-Sell Kane. Observing how the team has evolved over the past year or so, Kane does not fit well within the system that has recently worked for Tottenham. Keeping him is a lose lose situation for both Kane and the club.
-Build attack around Son as #1 and Moura as #2. Clearly this duo has been working on the biggest stage and against the biggest clubs. I don't see why it wouldn't work going forward. Give Son more responsibility by making him the point-person up front. He still needs to be more consistent with his finishing and perhaps his passing but he has most of the qualities (pace, quickness, skill, ball sense, ambidextrous) that would allow him to be a top 10 attacker in the world.
-I would be inclined to try and sell Ali but if not, I'd move him up into a focused attacking role alongside Moura and Son. At times, he's asked cover most of the pitch but it's clear that he's not up to the task. A more focused attacking role would be more suitable for him at this stage in his career.
-Build some depth up front by signing a player or two with a lot of PACE and ideally, HEIGHT. Doesn't need to be the most expensive players in the world. Sign these players and develop them as the club did with Son. It's becoming more and more apparent that Tottenham needs to build their identity around speed, as many of the top clubs already have been doing.
Midfield:
-Sissoko and Eriksen are untouchables in the Midfield. Everyone else is fair game.
-Despite his recent poor performances, I think a replacement for Eriksen will be extremely hard to come by and even if Tottenham does bring in someone of quality, it'll take 1-2 years for the team to gel with the new playmaker. With a little time and rest, I think Eriksen will be back to form. I would try to keep him at all costs.
-Just like the attack, Tottenham needs to build more depth in the midfield. You could see the fatigue kick in during the latter stages of the season.
Defense:
-Defense looked pretty solid and organized throughout the entire season so I don't think there's much to do here. I think time and experience will only make the defense stronger, should Tottenham be able to keep the core together.
-Love Danny Rose, particularly in a system where pace is instrumental. He's indispensable in my opinion.