I kind of thought there may be obvious things that could change. It's kind of unusual to get such bad problems in such a relatively short time of training, other than traumatic injury like I said before. Best of luck on that. If you need further tips on form go ahead and post away or even start another thread since that could be useful for many.
You know powerlifters do what they have to do to get the job done so creating a shorter distance for the bar to travel, etc.
But you really have to consider the "box" that someone is coming from. You can't take all advice blindly and there are things that you may not know about the advice giver, such as their chronic shoulder problems
You have to consider what works for you and the risk versus reward involved. Plus you have to consider the difference between what goes on in comps and what is a sustainable way of training.
When I see someone say "you should only use a partial range of motions on bench press" or, in other words, only bring the elbows down to torso level, the first thing I consider is they probably have their elbows flared out and are using a somewhat wide grip. So to them, anything other than partial range is uncomfortable or painful. Yet the advice seems to come from some right way wrong way thinking rather than what it really is: an intrinsic limitation of the way they bench press.
Likewise, you'll get someone saying never use a partial range of motion. This person may do everything "right". Neutral grip, shoulders tucked at not more than 30 degrees or so. Shoulders down and scapula retracted. But even given all that, thoughout years of bench pressing and working to get your numbers up, your shoulders take a beating. A partial range of motion may be just the thing to take a little bit of stress off the shoulders sometimes. Not to mention the obvious use of board presses, etc. to work the sticking point.
Anyway, it's great if you switch to a neutral grip. Try not to let you elbows flare out too much from you sides (find the position that feels best to you), keep your shoudlers down and scapula retracted, chest up, all that stuff. But nothing is fool-proof so I guess what I am saying is you can never just just "leave well enough alone". You always have to be thinking, adjusting, and learning. There can be a little value in all sorts of places and the trick is to know how to figure it out.