I don't see why any of this matters when Ichigo's AOE is enough to cover Thor's entire body. Making both his immortality and regeneration kinda useless.
He can close the gap between them if he uses Warrior's Madness, but from what I'm seeing it isn't an in-character action as it removes his cognitive abilities and transforms him into a beast of war; which he seemingly doesn't like as it causes him to attack friend and foe alike.
I think he especially wouldn't use this ability as the fight is taking place in NYC, which is home to millions of humans. I doubt he would use this ability when there's that much innocent people are around him.
How likely is he to use God Blast, how does it activate, is it a beam that can be dodged or overcame through sheer AP etc.
He also needs to get this off before Ichigo just Shunpo's over and destroys his entire body with a Getsuga.
The profile says it's a "former" ability he has, so I'm not entirely sure if he can use it in this fight.
Yes, Ichigo can resist a multitude of different soul-based attacks, be it soul damage, soul destruction, soul erasure, soul absorption etc. He also resists all of these effects on a layered level as well.
Speed Equalization doesn't disallow the usage of stat amplifications, Ichigo can still use Shunpo, which is a stat amp that allows characters who are relative with each other in speed, to blitz the perception of one another. Unless Thor has evidence of him being capable of reacting to this level of speed, he's getting his perception blitz'd by Ichigo's movements when he uses this ability.