that all seems prety sensible to me and nice mix by the way!
what is he eating in the way of fibre? are you giving any maize or starches with his meats? A few things I would recommend for the amount of exercise etc he is doing are: to keep offering him 2 sittings a day, for chicken keep the portions to maybe a breast and a handful of whatever else, (i used to feed mine on the meat of the day, a handful of maize and then a little bit of kibble.)
Kibble is the dried food you may get, in this country it would be IAMs or Burns, maybe james wellbeloved. Not sure what brands you have there, but If you remind me which country you are in I am sure I could look it up, a lot are international. The good thing about these kibbles is that they have already worked out the balance for each type of dog, as in in each individual kibble there will be protein, fibre, sugars, fats balanced for the type of dog on the front of the pack. When you feed them yourself (which I am personally a fan of to be honest) it is more difficult to get the balance right.
Don’t run out and get cheap kibble btw, Im sure you dont need telling. Its just full of additives and your dog will eat it, but its not particularly good for him.
Runny or stiff poos sound like fibre imbalances, ofc Im not a vet and I could be wrong so don’t take me as gospel. Try and put less meat more fibre in his meals, if when he does eat he only picks out certain bits, i.e. the meat or veg or whatever, it may be a good idea to move to kibble, if he doesn’t want to eat it, stick some gravy or stock on it. I would hope he will eat it maybe not at first unless it smells really good, but either when he is hungry or after a long walk or something, but still only offer him meals at certain times in the day. Dont let him think that he can eat whenever he wants coz he will get lazy and not eat (stupid logic but for some reason it works).
However you want to do it try and get him eating the right amount of fibre and see if he improves at all, if in a couple of weeks he is still having irregular poos, it could well be that he has a tummy bug and you may need to see a vet.
IF he is starting to get funny with your bf, he is probably starting to think about testing the water, like many teenagers. To re-enforce your bf’s position in the household as it were (or the pack for doggy brains), it is a good idea to get your bf to feed him and walk him,I guess that you go together, so get your boyfriend to hold the lead and keep him in check etc. I recommend handling the food with your hands as well so that your scent will be on/in it when he eats. Admittedly though this should probably wait until he is eating properly.
If you can think of anything else or I have misinterpretted anything keep on posting coz i really don’t mind sharing my experiences 😛 in fact i kinda miss that job now