Er, I'm thinking about players of all skill levels. It just becomes more apparent how powerful those shot types are when on Lunatic, since it's the one with the most bullets. I think instead you're looking too far into what I said and are just thinking "oh no! he wants my favorite types nerfed!". Even if that wasn't the case, if you want to ignore the existing problems on higher difficulties for the sake of Normal, you're being a hypocrite. Think about the more skilled players.
Have I said how MarisaB should be nerfed? Would you like to know? Put a cap on the number of power items you can retrieve per bomb. Limiting you to only be able to get two pieces out of each bomb would mean you get a maximum of six pieces per life, one of them being a life piece. With this, you couldn't spam bombs for free lives, nor bombs. Are lower difficulties affected by this? No. Additionally, I would let the bomb run out sooner than it does. Currently it takes about nine seconds to vanish, and during that whole period you can shotgun while invincible. Limit it to less time and it's less abuseable. Does this affect lower difficulties? Yes, but the problem exists on all of them.
As for SakuyaA, limit the range of its homing, soften how much slower the enemies get, and nerf its explosion damage. Changing how slow the enemies get will vastly affect Lunatic, but if the enemy you're hitting doesn't shoot many bullets to begin with (i.e. lower difficulties), then it isn't as big of a deal slowing them down in the first place. She doesn't need a huge nerf, but it's apparent her focused shot is overpowered. Her unfocused shot on the other hand needs buffing. The fact that you say "it's useful!" for both shot types means either you can't see how powerful they are, or you don't care and just want your personal favorites to stay as powerful as they are.
Seriously, jeez, it's a critique of how the shot types are balanced. ZUN's shot type balancing does need work in basically every game to some extent, and in particular he has bigger balancing problems with gimmicky characters. Balancing the shot types out gives you more diversity in that people can actually use a multitude of shot types and not just using one or two types because they're just better. Do you acknowledge how overpowered ReimuA was in SA? The other characters might as well not exist if your goal is just to win. Is that diversity? No.