After playing with this character for a bit, I'm not entirely sure what to think. There's definitely potential, I think you have a good thing going on with the jump and spin abilities (they affect your Y axis and not the Z axis by the way), but the rest of the abilities don't have much purpose, if at all.
The hover I can probably see being used a bit, but the cost to use it being 10 rings with them draining even after doesn't drive me to utilise it more. You can still hover while in Super-mode, which is strange but not bad or anything. But, it's even stranger that it's been put on Custom 3, which it shares with the less useful projectile shot.
I'm not even sure why it exists since there are plenty of other and easily quicker ways to destroy enemies. You're not even able to properly aim it up and down, which doesn't help with my feelings towards it.
And then there's the Custom 2 ability, which shouldn't need to exist if you're able to reach dashmode instantly with the spindash. That sort of just makes it a waste of rings.
If you're going to make a character with ring-centric abilities, giving the player free access to them is pretty OP and definitely not the way to go. Look at Golden Metal Sonic. It perfectly manages the use of rings with abilities in a way that doesn't hinder gameplay nor give it to you for free.
What I think this character suffers from is not having a sense of direction. It doesn't know what it wants to be, and the mishmash of abilities it has makes that kind of obvious. Since this is only the first version of the character (as I'm writing this review), I can only expect it to improve, and I sure hope it does.
But, first things first, decide what it is that you want to do with it. Making this character everything isn't working out.
(Let's get this out the way, it is the Z axis as SRB2 is a 3D game, the Z axis is the only vertical axis in this, and is heavily referenced via z-named values, such as the .z position, the z momentum 'momz' and P_SetObjectMomZ (or even in devmode if enabled to show the Z position))
C2 exists as you need to stop and charge up if you want to reach dashmode instantly. With C2, you can instantly reach it (and even redirect momentum if in need) in any state, of course for the cost of 15 rings. The hover can be useful as it's a, hover, as long as you can collect the rings to maintain it. The laser was assigned C3 with C2 as C2 can be used at anytime, whereas the hover only really makes sense to be usable in the air, hence why the two got merged into one button to, attempt to use less power. That being said yeah the laser is useless but it was made for Chaos in mind, and sorta balanced around Battle... Why did I do that...
The super flying is basically an emerald reward, to really motivate into collecing the emeralds.
But the real utility of C2 and C3, is maintianing rocket state. In the rocket state, and in dashmode, you can't take damage. If you jump or spin for example, you exit the rocket state, and need to land. However by spending rings to hover or boost, you will be put back into the invincible rocket state.
Sorry for the long winded message but I felt like I kinda had to elaborate on this. I don't consider it, "Free access" as 'free' is a cost of having to stop in order to charge up.
Though yes.. I do agree that the Overview could be greatly improved, but for now I just wanna rest lmao