Bettas are awesome fish, and very hardy :) They are more than able to adapt to different water levels, so just be sure to acclimate him or her well.
Twilightnite: well, I rarely see my bettas poop, but I know they do. So long as he is healthy and looks and acts fine, then he should be alright :) if you are truly curious and/or worried, keep him in a clear bottomed tubberware for a day, that way you can indeed verify he does poop.
GreenTea: how much water are you changing out with each w/c? Once he looks fine, then stop the epsom salt usage. Ten days of salt exposure is the absolute max. Once you are done, do not use aquarium salt... just good old clean conditioned water. IMO, salts are just for treating ailments; when bettas are constantly exposed to salts, their organs might fail.
Also, I feed pellets because flakes tend to be extremely messy and less nutritious. Give him a while, some bettas take a few days to get used to their enviornments before they start to eat. A healthy betta could techinically (though DEFINATELY not advised) go a whole month without food. He'll eat when he's ready. If you are concerned the pellets are too big, presoak them and then cut them to manageable chunks. If he spits them out, remove the rejected food and offer him new food whenever his next meal is.