Parkman finally grows a spine, unfortunately he unwittingly works for President Sylar.
Sounded like Claire's dad took a bullet after Parkman got her 10-20 from him.
Why does future Hiro think Sylar acquired Claire's healing power especially since in his timeline she is alive? (Well until she meets Mr. President.) My guess is that he assumed Sylar has her power and in his research, Hiro was mislead by HRG into thinking his cheerleader daughter was killed by Sylar.
Does Peter blow up the city by accident or in a vain attempt to kill Slyar? What your best guess?
I don't think Slyar used the 'doppleganger HERO skill' to fool Hiro into stabbing someone else. That girl used that power to disguise herself not others.
Peter's scar looks like it's from a sword blow. If Hiro mistook him as Sylar in a fight that would explain why Hiro saw someone heal. Of course that doesn't explain why Peter didn't later set Hiro straight.
Perhaps Peter couldn't heal himself because the Haitian intervened at some point between when he received the cut and before he completely headed, and stopped his healing power. At least partially and so he scars.
EDIT:
DaWhim's post above partially answers one of my questions. (I hadn't seen his post before I started mine.)
Sylar got DH power too...
what happened to DH and micah?
Didn't Peter explain to Jessica that he blow them both up?