Yaaaay. This is my favorite windows game, and a lot of it has to do with the shot types.
Reimu: 8.5/10 (9/10 for PD, 8/10 for Legacy)
In a game based around streaming, killing as many enemies on screen as possible, and full of suicide bullets, homing is a necessity. Sadly Reimu's homing is unfocused making it difficult to stream effectively. Still really useful for stages.
Her focused shot is really meh. Sanae deals just as much damage at full power (since Reimu can only get 3 options to hit the boss). Marisa is waaaay stronger. And Reisen is Reisen. Still does it's job well enough, I guess.
The bomb is by far the worst in the game- it clears bullets so you can't super graze, and it doesn't even last as long/do as much damage/clear as many bullets as Master Spark. On PD where you need to conserve your bomb or in No Bomb runs this isn't a big deal, but in Legacy the awful bomb is really noticeable.
However, the thing that really helps Reimu keep up with the others is her smaller hitbox. I can actually capture Ringo/Doremy/Junko's nons...!! Really, if you're used to playing with the bigger shrine maiden or the fat rabbit, you will notice the difference immediately.
Marisa: 6.5/10 (7/10 for PD, 6.5/10 for Legacy)
Marisa is a sad case of being a good shot in a game full of over powered shots. Marisa deals way more damage than any other shot. And I don't mean the usual "more damage", I mean she deals as much damage from the bottom of the screen as the frogs do when Sanae is shot gunning. In almost any other game, she would be top tier.
But sadly, like I said, this is a game where homing is a necessity, and Marisa does not have it. She doesn't even have a wide spread- her lasers still have the issue of being super narrow. Even though she can crush bosses, she fails on stages. And stages are you main source of resources in this game, so you'll be working with less lives than any other character.
Unless you really want to PoC, Master Spark can do everything Fantasy Seal can and it can do it better. It's stronger, it lasts longer, and it can clear most bullets thanks to the tilt. Unfortunately, it still clears bullets immediately, so you can't get that graze. Which is a big problem.
Sanae: 10/10 (9.5/10 for PD, 10/10 for Legacy)
This is my favorite shot in the series. It has something for every situation.
The focus shot is homing snakes which double as a forward focus type. They're as powerful as Reimu's needles. They utterly obliterate most stage portions, and since it's focused homing it means you can super stream easily.
The unfocus shot is high power,spread, splash damage frogs. It covers any stage portions that the homing can't and it destroys Sagume.
Even in PD where you want to conserve your bombs, this shot is just so versatile and easy to use that it makes up for the larger hitbox.
But once you include bombs, this shot becomes perfect. The game gives you 3 bombs per extend. You need 3 life pieces for an extend. Sanae's bomb is very long and it doesn't clear bullets immediately, so you can bomb then sit on top of the enemy gathering a ton of graze. Not to mention that it's the strongest bomb in the game.
And it's still well balanced. Using this shot, you still feel like you're playing the game as it was meant to be played, unlike with DDC Marisa B.
The only weakness is Sanae's large hitbox.
Reisen: 10/10 (10/10 for PD, 10/10 for Legacy)
The bomb. That's basically it.
The focused shot is weak and piercing is not incredibly useful outside of killing Sagume's familiars and Junko slaying.
The unfocus shot complements her focus shot well, a strong spread type on a forward focus type, but this is not the game for it. It isn't wide enough to let you cover the screen like with Sanae's frogs, and it isn't homing, so you still have to work to kill all the enemies.
All around she's decent in theory, but like Marisa this game was not made for this kind of shot.
But none of that matters, because of that bomb. It gives you 3 extra lives until the end of the stage. Yes, dying won't clear all the bullets or give you a ton of invincibility frames, and yes, your hitbox is bigger. But with 3 bombs, you can get hit 10 times per extend. That's just ridiculous. PD doesn't play much differently since you don't have to worry much about bomb conservation. On top of that, the bigger hitbox also means a bigger graze box, so she can get her resources back faster than Reimu or Marisa (or even Sanae, if you're good).
Loses most of its potential if you'r trying to no bomb, though.
I will say, though, excluding Reisen, Extra is the great equalizer. Since the stage portion is already so easy Sanae's stage killer shot goes to waste, and her bomb is useless too because Extra. Reimu's smaller hitbox and Marisa's higher power are both quite a bit more useful when the focus is on beating the bosses like in most games, rather than super resource gathering. Reisen's bomb is still totally nuts though.