Fighting in clinches should be universally allowed

That last statement isn't true. A significantly larger man (either with a big weight advantage to begin with at heavy, a'la Klitschko vs. Povetkin - or via deep cutting and rehydrating a great deal more a'la Broner vs. most of his early career opponents at super feather and lightweight) allows the bigger man a functional strength advantage simply by laying on & smothering their foe and sapping their energy without allowing for any of what constitutes legal "clean" infighting. :nono

 

hell no, this would just encourage fighters to use rabbit punches as one of their main tactics

 

Something of which we absolutely don't need any more. :deal (speaking of things for which refs don't penalize enough)