All valid points, in fact you reminded me why I made the initial gun way faster at the beginning of the development, but then I eventually ended up making it slower to make the other guns feel more useful, but it might just make more sense to have the main gun be more like touhou standard weapons and shoot really fast with weak power, then add more projectiles and effects as P is collected.
About freezing: I recently implemented a bullet freezing mechanic similar to Great Fairy Wars, right now it's just a panic button but I'm thinking it can turn into something more involved in the gameplay, I still want to keep the focus on the weapons, the in-story reason is that magic does not work as well in this cyberpunk world as it does in gensokyo, Cirno's main strength is being able to come back from death as long as she has motivation.
You aren't the first person to complain about movement speed so that's definitely something that needs to change, I'm also considering eventually implementing status effects so that freezing can be something ice weapons shots do, it's just hard to not accidentally make some weapons so overpowered that there's no reason to use other weapons.
You also just gave me a great idea: Cirno could float all the time and have some friction to speed up and slow down, unless focus mode is engaged which would make the speed constant, in order to avoid bullets, this also solves the issue of having cirno face one way while she shoots another way, she can always face towards the direction she's shooting at if she floats and it will still look good