All R1+square moves have 1 hit of armor, idk if that's what Tsuna does with that input but that should go through 1 hit projectiles.
There's a lot of moves that neglect/stop projectiles tho, like Raoh's orb of manliness, Zebra's jelly box, Aizen's Danku, Saiki's Molecular Shield, Nube's Book shield etc
You also always have the just guard option which is character dependent but most will work against all projectiles.
As for Tsuna he's high tier imo. He's really good as he has everything, he has a beam (X-burner) which is always useful, he has an auto combo special that you can do after his string which does solid damage, he can fly and can use both his O specials in the air (very rare). He also has a counter which you can hold for as long as you have meter.
The only thing that he "lacks" is a great super but his isn't bad, you can still combo into it and it does good damage.
Plus even if you think it sucks then leave the super stocks for your partner to use, Tsuna doesnt need supers to do good damage