1) No, he hasn't received any warnings. Perhaps he expects them. 2) What was pulling him? If a crowd of people is doing the action, then you can understand "pulled" as "forcibly taken". 3) I don't understand why "are refusing to" could be a better alternative. This is a conditional, so it's far clearer to use present simple.

1 I have yet to receive such warnings. （You have not been informed by anyone about problems/ dangers/ illegal issues with whatever they are talking about.) 2 He was being pulled out of his house. (He was physically being removed from his house, pulled out) Why the author use "refuse to" not " are refusing to " in the sentence below ? If you refuse to turn in the gun, you could be charged with a felony. (either is fine grammatically, "are refusing" is occurring right now, "if you refuse" could mean a less definite time, maybe tonight, tomorrow, etc.