There are more ways to deal with fire than with rain and are more precise in dealing with it. You can also choose to ignore it if you have the resources. The point is you have resources at your disposal and you're choosing to ignore them for reasons you have not explained yet. Hence, it's a hyperbole when you say you can't live without rain.
Your point about rain does not reflect my experience at all since there are so many ways to deal with burning or fields of flame in general. Something is only detrimental if not having it does not allow you to play your game plan. I would almost want to argue that your usage of rain is a crutch rather than an alternative.
Your combat effectiveness is determined by a mix of skills, abilities, gear, and context. In some cases, each attribute point beyond a certain threshold gives less value than a point of a skill would.
Certainly, some skills need to be reworked, but you really aren't weighing them at all in your current analysis. Some of those advantages are kind of massive too as well as opening up playstyle specific tactics.
As for zoning the opponents what you say is pretty much true up until you say that zone control ceases the moment they reach you. You have just as much mobility if not more than your opponents do and there are PLENTY of situations where even after they have arrived at your threshold you can still control their movement (by withdrawing then CCing the area or teleporting them back etc). There are also plenty of situations, due to positioning, the enemy will not reach you in its entirety till the second round.
And, yes, it's true, they can run through your lands of fire and lightning but they also lose out on their magic armor along the way which... makes them vulnerable to CC. Zone control is still effective as it makes the opposition pay a price. Just remember whatever the enemy can benefit from you can as well. If that's the case then it comes down to simply playing your cards right.
As for the last point, let me rephrase it and say that memory has a pretty good relationship with combat effectiveness. There's always going to be a break point for what you want and that there is more than one way to play.
