Interesting topic, and my love and tolerance ends at a cretain point, of course it does...
For me that is when I notice people (not just friends, everyone) being bullied, harassed or anything of that kind, in real life. If that means to go against Anti-Bronies, on the Internet mainly I try to stay calm and explain, or just leave when I think it's of no use.
That is where the love ends and where I can become really uncomfortable, but that's an exception.
About being lumped in with furries xD...
I am a Furry, and a Brony, there are things same about those 2 fandoms and things that are specifically for Bronies or specifically for Furries. I try to explain, but I stopped wondering when people throw those 2 together x3.
The word R34 doesn't make my skin crawl...
I'm really grown up enough to just decide when I like something and look at it or not like something and avoid it. I don't get how some people get frustrated and damn a whole fandom for people enjoying or creating nsfw material...
It's really just another part of the fandom we are a part off, and you can always stay away from it, if you wanna.
About the flaws as a Brony...
xD I really dont know, I don't think it's a flaw that I try to be the nicest person I can be. You could say I have flakws because I can't always manage to stay friendly and loving, for example after a long, stressfull day, but hey, I try.