My personal view on this matter is that I would not start or provoke a conversation with anyone about religion. I am an atheist, leaning toward anti-theism, but the fact I am an atheist means I have no particular interest in religion and have no inclination to prompt a conversation about it with other individuals.
For that reason, I am perfectly comfortable with the idea of "respect", and not "foisting" my atheism on other people, regardless of whether or not they share my views, and also regardless of which particular religion they might align themselves with. I do, however, reject the idea that if I'm asked, or someone prompts me to engage on the topic, that I somehow have to moderate or water down my response for fear of offending.
The same rights that mean you are free to worship anything you choose also grant freedom of expression, and that means the right to criticise, and even offend, provided you stay within the bounds of legality. As I said, I am content to show "respect" by simply never bringing the matter up, but this only works on a reciprocal basis, and if religious people actively seek to bring the matter up, I will oblige and engage. I also believe that as Christianity is a pervasive, insidious presence in UK public service and politics, I am perfectly entitled to express my view on that matter, since it does directly effect me, and I'm subject to the whims of institutions and people trying to foist their belief system upon me irrespective of the fact I do not share their beliefs, and quite possibly do not share their "values" either.
On the point about Christianity being "singled out" and Christians feeling "bullied". I can understand that perception, but then I think that is just a natural consequence of Christianity being the overwhelmingly predominant religion in the UK, so it follows that as a matter of course most of the discourse revolves around Christianity, so you are going to end up with more upset Christians than any other religion!. They are certainly not persecuted in the UK, so I have a hard time feeling any sympathy when they claim victimhood. The allegation that nobody would dare respond to Muslims, Jews, etc in the same way is a nonsense. I hold all organised religion in contempt, but again, I'm happy to keep those views to myself unless prompted. Who, precisely, prompts the response is neither here nor there, and I would not dilute my response or be shy in speaking honestly depending on the particular beliefs of who I am responding to.
I'm puzzled as to why people who claim faith would be offended by playground insults like "sky fairy" and "delusional" in any case. You, by definition, believe in something that is entirely without provenance and can not be proved or disproved other than philosophically, and even then only after you have defined what it is that you actually believe. Surely, if your "faith" is strong enough to actually believe, then mere criticism is nothing more than water off a duck's back. This is why I always say to overbearing religious people "if you want to stop being ridiculed, then stop being ridiculous". Engage in good faith, and stop expecting those of us who don't believe to "respect" something we regard as palpably ridiculous. If you ask, then don't take the huff when you get an honest response.
Russell's Teapot. Nobody would have the slightest concern in "offending" anyone who espoused this nonsense, so why should other, equally implausible belief systems expect a special stats that grants them freedom from criticism, mockery, or ridicule?
Mockery and satire has always played a fundamental role in exposing the ridiculousness, pomposity, hypocrisy, and illogical nature of organised religion. It's a big part of the reason why fewer and fewer people oblige it with the special status it constantly demands. I utterly reject any idea that it, or people who follow it, should be given special protection from other people simply expressing a view they are perfectly entitled to both hold and voice.