With respect to his eating, if you're concerned he's not eating, and at this age you are right to be, get a scale and weigh him once a day AT THE SAME TIME (before the first meal for example). If you have a good scale you can weight yourself, pick him up, and then weigh the two of you, but his weight is such that a separate baby/pet scale would be much much better. He should still be putting on weight at a pretty good rate. IOW he should weigh more on Wednesday than on Monday. (You like to see an increase every day but measurements can be off because of you, the equipment, or the active dog, or natural variance -- or all of the above. The two day measurement should be more reliable).
As long as he's gaining weight and looking good then you should be fine. If not then you may have a problem. FWIW from the picture he's adorable and looks healthy. Super cute actually.