I'm going to break this down as kindly as possible.
There is a lot going on in your system and you are posting about it very often.
You have sick fish, which is the outcome of the parameter issues...I also think I pointed out aggression earlier as well as improperly cycled... The hermits being 'lazy' is either from him standing there eating for long period of time OR that it is stressed out from parameter issues.
So, where to go from here? Simply. LARGE water changes with ro
water. I'm looking towards 50% of the water column twice a week on top of the 10% that you should be doing weekly.
You need to cut down drastically on your feeding, as it is feeding the nutrient problems in your water column. You will need to target feed your watchman goby gingerly as throwing as much food into the system hoping that it'll get some scraps will turn your water column into major nitrate sinks.
All in all, there is an impression being presented here that there is a lot of money being thrown into this system to 1. correct issues you are identifying and 2. getting things that is believed will look nice in your system. This hobby requires major patience. Throwing money at it won't fix anything...I and pretty much everyone else has tried.
So, to solve your issues you need to do water changes and slow down. This might not be able to save everything in your system, but it is what is necessary to save what is salvageable.