Controls are fiddly, I think that's fair. Largely a reflection that the underlying systems are much more sophisticated than previous Zelda games. It's a shame they don't give you the option to fully remap the controls, but after an admittedly long period of adjustment I've reached the point now I'm comfortable with them.
But the rain? It is a fundamental part of the simulation that is key to making this an effective and enjoyable survival game. Personally, I'm thrilled to play something that doesn't just use it to make it harder to change direction when running. Here it puts out fire, makes surfaces slippery, interacts with electricity, and likely does all manner of other things I've yet to discover.
It's one of the many elements that makes this - quite unlike any other Nintendo title - a game which will give you 100 unique stories to tell.
For example, last night I climbed to a high point to attempt to glide across a canyon. I knew it was 50-50 whether I'd have the uplift to fully breach the gap, but with my recently improved stamina I knew that if I fell short I ought to still be able to climb the rest of the way up. So heroically I launch myself from the highest tree on my side of the canyon. Unfortunately, I am in the air less than 10 seconds when it starts raining.
I think the rain must add weight to my glider, because my angle seems to detoriate a little and I crash against the cliff edge on the other side. Link helpfully grabs on automatically, but the cliff is a sheer 90 degree angle. If it were dry I'd have no problem, I could climb up the last 5 meters and be exploring a brand new continent in a matter of seconds. But no, it is raining.
I try to climb anyway. We get about a metre further up, but then the rock gives way and Link starts to slide back to where we started, except now with a little less precious stamina. I check my inventory in case I find an item I'd forgotten I picked up that improves my grip, but no such luck. I try to push up again taking a slightly different route, but the result is the same. The only way is down.
What is at the bottom of this canyon anyway? It was too deep to easily see from the top. I slide slowly, carefully down. Soon it becomes clear it's a river, but with no banks to rest on either side. And of course at this point, Link is exhausted. He has no stamina for swimming. He drowns.
Annoying? To some maybe. But this game autosaves pretty frequently, so I've not lost much progress. And this game generally gives you at least half a dozen ways of achieving your ends, so when I reload I climb down the tree I'd tried to glide from and look into other ways to cross the canyon. I spot smoke in the distance and follow it to find another traveller who tells me a few legends about what's on the other side, says that there's a bridge out to the east, but it's a long old road. He also says it would surely be folly to try to cross any other way...
I could go on, but safe to say as I headed out east there more exciting, tense, funny moments of emergent gameplay, that makes me think this really is the first game to live up to the term "sandbox".
If ever you were inclined to give Nintendo a second chance, I assure you this is the game to try.
See smarter people than me talking along similar lines
here.