I don't think Teach knows that Ace is persuing him, or he'd be a little more on the defensive. Instead, he's focusing on making himself a name so he can become a Schichibukai. Course, we don't know his fate after his ship is destroyed at Knockback Stream, but it's safe to assume he survived.
One thing that bugs me, though… why does everyone assume D is a bad person for killing a nakama? Granted, it's something a D would never do, but we don't know any details about it, nor the situation. Perhaps Blackbeard's life was threatened, or the nakama was a threat to a great many people. Shanks seems to know something about the nakama that Teach killed, because Newgate knew what Shanks' letter was about, or thought he did.
Statements like, "For a kid with such ambition..." makes me think that Teach just has a bad rap. He's not a bad person, per-se, he just comes off as one because of his monstrous size and fearsome appearance. Roger could have been the same way. People could have feared Roger cause he was a HUGE man.
Saul is the only exception to the rule, but that's because of his appearance. Saul doesn't look intimidating, even though he IS a giant. His unusual laugh also makes him more approachable than Roger or Teach.
Perhaps we need another young D to balance it out. Someone like Luffy or Ace, but one that looks very very fearsome, like a devil child of the family.