Thank you all for the replies, I will certainly take them into consideration.
However. Have you ever seen a swimmer with narrow shoulders? I have not.
The main idea behind swimming (as well as the program outlined in the tread) is to better develop and broaden my shoulders, within their limits of course.
Swimming can help in that respect and would be done mainly for aesthetic reasons as to broaden the shoulders.
While the issue encountered last weekend is certainly an element of concern I still think it was an overuse reaction after an already loaded week of shouldertraining that isn't normally done either. To continue the story. 18 hours after the swim, the pain has subsided and only fatigue remained. 36 hours after the swim, fatigue was gone and recovery mostly complete to the point where 48 hours after the swim a normal 5's training could be performed (even at 5's, I only use like a 3.3 pound dumbell which is pretty light for side raises). I think this is pretty good, since usually, muscle soreness is at its worst during the second day.
I have been swimming, even just the week before on holiday multiple times, before with zero issues on the shoulders. Granted, it always was without doing shoulder workouts and for shorter bouts with more frequent rests during a single session.
I know diet is controlled in the kitchen, that is what I do also. However, have you seen any competitive swimmer that isn't cut? I have not.
From personal experience I know that swimming puts my metabolism in race-mode like no other form of cardio ever would. It is almost like if I was on DNP, the way I'm burning calories like hell. Like other swimmers reactions I've seen, I'd have to be carefull not to overdo it dietwise, or I wouldn't add a single pound no matter what I ate.
However, in this case the idea would be, during the bulk, to help slow down the weight gain if needed, as in preventing a quarter to half a pound a month at most. So, really the polishing stuff. During a cut, as well, to make the weight loss just that bit easier. I think for this reason, swimming could be excellent, as only already the fact of being immersed in colder water gets you to burn calories, just to keep your temperature in check.
Given that aside cardio, through the resistance of the water, it is a full body exercice, would make it pretty ideal for both aesthetic and weight loss goals, more than any other form of cardio.
As a consequence of the above the shoulder workout has been greatly reduced.
The Front raises have been skipped. I will stick to Landmine presses as those have not given me any problems during the previous hst cycle and are probably enough stimulation for the front delts.
The band pull aparts have been skipped as well but are replaced with shoulder dislocations, a no weight exercice that has given me fairly good mobility and rehab results in the past.
Lastly, no more then 3 times a week instead of 5.
I don't know about the swimming at this point. I might have to skip it, if it is really too much. But I'd like to keep it for at least once a week. I might need a sort of 'start to swim'-program with a slow build up starting at something like twice 4 x 12,5 m with a 30 sec. rest in between each lap (so 8 rests in total). I'd prefer back stroke since it doesn't target the front deltoid specifically and is a similar movement as the shoulder dislocations which could be beneficial for shoulder health.
If indeed, the lightest start would still give me issues, then sadly enough, I would skip the swimming, as I like to swim and can see the great benefits it can potentially have.
I have to deal with the shoulder as it is and make it the best I can. As I cannot change the way the bone is formed, it is beyond repair. I can only work around the issues of concern (no overhead or behind the neck-anything), trying to work on mobility (shoulder dislocations), balance (internal, external rotation, scapular elevation and depression) and strength.
