fish personalities?

I have quite a few small feeder size comets several fancy type
goldfish and a big Koi (8-9"). I used to have a routine of feeding my
fish. They would all hover I would throw a bunch of flakes to them
and they would begin eating. In the meantime the koi would probably
be in the area but trolling the bottom. As the GF started finishing
the flake I would throw a smaller amount of small pellets in. The GF
didn't like the pellets as much and some were too small to eat them.
Usually the koi would surface and eat some of them. I was overfeeding
the GF. As I have cut back some of the fish are a little now and can
eat them and they seem to have decided those little pellets are so bad
after all, while still preferring the flakes. Generally there are no
leftovers for the koi. I tried a bigger pellet for a few day, but
became concerned that the larger GF were scarfing them down to their
detriment. Some would flip and shake like they had something stuck in
their 'throat'. I wait till 'he' is apart throw a few in a usually
the other fish come get most or all of them. He has begun to hover
with the pack (unusual) when I come to the 'feeding station'. He
still wants to stay below by in large and get the stuff that falls
down, but there is not much of that anymore between smaller portions
and the others being more agressive and less selective.
My problem - Often after the feeding he will cruise around, search
the bottom some then start swimming around faster and then start
flashing around or on a few of the folds in my liner. I rarely see
him doing this except after feeding time. I am not sure if he is just
trying to tell me "Hey did you forget about someone?" or if something
else is going on. He does still bottom troll, but it seems less than
before. He has also been hiding much more under plants and a little
waterfall ledge that I have, although that might just be because it is
much brighter and warmer in Texas now than a month ago. I am mostly
wondering if he is just adjusting to the new feeding schedule or if
something else might be going on. I have been posting about concerns
over high PH which I have still not solved or figured out. Perhaps
his behavior is really because he is more sensitive to this. Boy do I
fret over smaller details now! Any ideas? Oh, and should I be
soaking the larger (medium size) floating pellets before putting them
in?
Thanks - Bill Brister - Austin, Texas