I'm glad that your sister is going to a fine university. Go Tarheels!
As a gun owner and a NC resident, here are my thoughts about what your sister said or wrote.
1. Essentially, it offers immunity to anyone who "shoots first" and asks questions later...
Well, I sure hope so. I have no intention to ask a home intruder what his or her motivation is. Anyone who enters my home that I do not know must always be viewed as a threat first. This is a natural, human response. It does not imply, however, that I will always shoot.
2. ...removing the responsibility to try to evade the threat to retreat to protect oneself before using deadly force on someone unknown.
Tricky one. She assumes that retreat is a responsible act (might very well be!), but by doing so, she avoids the possibility that one cannot retreat or that "retreat" only gives a dangerous person an opportunity to strike first.
3. I don't think I trust my fellow North Carolinians, especially gun owners, to assess "a reasonable fear of imminent peril of death or great bodily harm."
There is no free lunch. It is true that someone might not do a proper assessment, but that could happen even if one "retreats." What I do know is that the law should protect me from being prosecuted for (possibly) making such an error in my home against someone who does not belong in my home. The law should favor me and not the invader.
4. I think this will increase gun violence
It might. The again, it might save innocent lives. Take yer pick.
5. ...and protect irresponsible gun users.
This is a loaded statement (no pun intended). It assumes that I and others are irresponsible. Sorry, it is the home invader who lacks responsibility.
6. It will lead to tragedies, not heroism.
Yes, taking a life is a tragic situation.