Not to bring you down from Valk's rushdown high (I know how it feels), you haven't played against a bang or anyone with 5a have you?
Valk's blockstrings are ridiculously easy to IB and bang's 5a is gdlk in this aspect to punish/poke valkenhayn out of his blockstring/combos. And you know how it goes against bang when you don't have any reversals.
In short, I feel that valk is too fragile to be playing super aggressively, especially against the likes of tager (ib 720/360), and S-tiers. You gotta play smart.