Physicists already know that GR doesn't work with Quantum Mechanics. It isn't 100% correct. Many are trying to figure this out. So, it's not really about if you are questioning GR, it's about how you are questioning it.
If your doubts about theories aren't up to speed with current knowledge, then you aren't likely to be taken seriously. This is not a simple undertaking, you are unlikely to parachute in with a bold new theory without years of study. Those "paradigms" have a lot of supporting evidence that can't be ignored.
I don't think it's about offending people, I think it's more like another tiresome waste of time from their perspective. Your questioning of the current paradigm has to break through this bias by showing that you understand the current theories and by presenting an interesting new approach that addresses problems with the existing theories which is fully compatible with the existing observations of the real world.
Einstein was a patent clerk when he wrote some seminal papers in physics. Then the academy did take him quite seriously. Same with Ramanujan in math; he wasn't known until after he showed his work. I believe it can be done, but it's pretty rare.
Finally, there's no point in complaining about Reddit moderation at Physics Forums. We didn't do it (yet). We don't even really know what your complaining about.