Triple Axel and Focus Blast are used because other options are worse not because they are good moves
It all depends on the circumstance.
A Physical Ice-type (not named Kyurem) would likely have access to either Icicle Crash and/or Ice Punch, Ice Fang if need-be. Where Triple Axel shines are for the non-Ice-types which niche it just so happens to cross. Yeah, it's not as "good" as Icicle Crash, Ice Punch, or Ice Fang, but if you're not a Pokemon that is going to get those Moves anyway but get Triple Axel, well, it's good enough (and sometimes good enough coverage is all you need).
There's not a lot of Special Fighting-types, infact usually when they are they are given a Special Fighting-type move (Lucario with Aura Sphere, Keldeo with Secret Sword). Thus Focus Blast is also mostly used as a coverage move by non-Fighting-types. Now there's only a handful of Special Fighting-type moves, Aura Sphere arguably being the best of them as it's decent Power and 100% Accurate. However, Aura Sphere's distribution is limited due to its flavor, and while some questionable Pokemon get it, those are more exceptions which prove the rule. If you get it great, but otherwise you'd have to work with either Focus Blast if a Special Fighting is what you think you need or have to come up with a different plan. As above, it's good enough.
Look, I'm not here to try and change your opinion. If you think they suck due to their inaccuracy that's your opinion (I myself am not a fan of inaccurate Moves). But you can't say they don't have a niche which they fill adequately. Pokemon is a game where you work with what you have, and sometimes what you have is an inaccurate move which (can) hit hard.
1. Water is now weak to Poison.
2. Ice is now immune to Water, and Ice is now neutral against Water.
3. Highly limit the distribution of both Scald and Ice-type moves.
4. I think Rain needs a much closer look in terms of balance, to the point that it goes beyond the scope of this post.
1. Hm, you know what, sure. If the idea of Poison being SE against Grass is because it's a pollutant, Water should also be vulnerable.
2. Ice neutral to Water, sure. But Ice being IMMUNE? No, gotta disagree on that one. The reason many guess why Water resist Ice (and why Ice isn't SE against Water) is because water as the element compound is able to retain a lot of heat, if it wasn't able to life as we know it wouldn't be able to exist. Therefore, Water-types have a natural resistant to Ice. But that thinking is very one-sided. It ignores that the Ice-type isn't just a animal that lives in/covered in ice, it's as much of an elemental creature as Water-types are. They generate cold, extreme cold, they have no problem freezing normal water. Maybe a Water-type would do fine in a cold/snowy environment due to their natural heat retention, but against an Ice-type they should equal out against each other. And as much cold as an Ice-type generate, too much water will wear them down, especially from a water elemental: it's also not just that the water has heat in it but also is being fired at a high velocity and Ice is structurally weak to kinetic force. Water =/= Ice is just fine.
3. Yeah, Scald's distribution feels a bit much. Not all Water-types should be able to superheat Water that it can cause a Burn.
Only two Pokemon naturally learn it: the Panpour family and Volcanion. I'm fine with both of that, Volcanion for obvious reasons and Panpour family I'll let slide due to their design origin (made to help the Striaton Triplets in the restaurant, specifically to make tea).
TM/TR is where things get interesting. Not going to go over them, so here's the one I would let keep it: Blastoise (it fires water out of a cannon), Tentacool family (can use chemicals of its Poison-type to make a burning sensation), Galarian Slowbro (arm cannon), Galarian Slowking (can use chemical to heat up/cause burning sensation), Seadra/Kingdra (is a sea dragon), Gyarados (is a sea serpent), Mew (cause Mew), Chinchou family (heats water with electrical energy), Remoraid family (its an artillery Pokemon), Milotic (is a sea serpent), Castform (probably has enough control over its metamorphic molecules to make water boiling hot), Luvdisc (as a joke), Kyogre (gonna give lord of the sea a pass), Emboar (a fire pig shooting out hot water, sure, let's move on), Normal Stunfisk (heats water with electrical energy), Dragalge (is a sea dragon), Clauncher family (claw works like a cannon), Inteleon (is a spy so has a few tricks to dish out hot water), Pincurchin (heats water with electrical energy), & Drakloak/Dragapult (a sea serpent that has cannons (of sort)).
4. Does Rain need a debuff or does the other weathers need a buff?
The problem with Water really boils down to Scald.
I see what you did there.
If there's one secondary effect that I think makes a lot of sense to put on Water-Type moves, it's flinching.
Eh, honestly being wayed down by water is more something I relate to Water, which in Pokemon would translate as a stage decrease in Speed. Also cold, but I think everyone would beat me up if I dare suggest a freezing chance (how about a Water-support move that makes the target weak to Ice-types?).
i love the water type but i think there are way too many water type mons.
Sus 
For example, when I first saw Barraskewda my first thought was "is this it?". I think that the fish concept has been done to death and that Game Freak could focus more on Water-types like Keldeo and Primarina, both of which are based on creatures that are associated with Water but it takes a different spin on them rather than just a fish.
Thing is there are a LOT of interesting fish so I wouldn't want to completely say no more fish-based Pokemon. They would have to combine them together with other things, which they actually did with Barraskewda which is a barracuda + torpedo (though this is hard to see in a still image). Infact on my
"What Isn't A Pokemon" Repository List I have a whole section dedicated to animals adapted to marine/aquatic like. And that doesn't include all the objects, prehistoric animals, concepts, and mythical things connected to the water, any which could b combined with the aquatic animals.
Also still waiting for the (bottlenose) dolphin Pokemon.
All I want for christmas is a WTF button.
What Pokemon would it be? I say a
confused looking Growlithe.
