He's got navicular, so you need to keep an eye on his sugar levels closely.
I'd look for a feed lower in NSC's than SafeChoice Original, it's not very low in NSC, perhaps Triple Crown's Low starch has a NSC value of 13.5 % and their Lite pellet has a NSC of 9.3%. I'd go with the Lite product honestly.
Safechoice is 22%, way higher than the TC lite.
Also at a pound and a half you won't get enough nutrients into your horse. If you don't want to change to another brand or product you could get some timothy pellets and add in a vitamin and mineral supplement instead and cut the safechoice altogether.
I'd also look at changing out the alfalfa for something else, maybe rice bran.
Healthy coat is okay, it won't do much harm. The other supplements are fine so long as they work for your horse.
Cut the treats and apples. You can give a few low sugar treats and maybe a carrot every few days or so and be fine with that.