You set out a threefold test for when repelling force would be justified and therefore provide a defence. I tried to make notes, and I think I captured it. I'll try to paraphrase it: first, the defendant faced a wrongful application of force; second, the defendant's response was necessary; and third, it was proportionate to the unlawful force that was being applied.
If I look at the proposed subsection 34(1) in Bill C-26, it also sets out proposed paragraphs (a), (b), and (c), where a person's not guilty of an offence if (a) “they believe on reasonable grounds that force is being used”, which is more or less that the defendant faced wrongful application of force; and (b) that “the act that constitutes the offence is committed for the purpose of defending or protecting themselves”, which is roughly your number two, “the response was necessary”.
Really, the only thing we're quibbling about is the third prong, where it says “the act committed is reasonable in the circumstances”. That's the proposed legislation, but you would prefer it if “reasonable” said “proportionate”.
Did I capture your theory correctly?