To this day, I can't put too many pieces of food in front of Tyler or he'll shove them all in his mouth...and he's 2.5! Toddlers go through all kinds of food preference phases, so if you keep offering finger foods, he'll get the hang of it. You might consider cutting back on his formula intake too. Around 1 yr of age, a big drop in appetite is normal, and he should start getting most of his nutrition from food, rather than formula. Drinking that much formula will probably curb his solids appetite, which can't be helping.
It's pretty normal for some kiddos not to be big sippy cup drinkers until the bottle is completely gone. Tyler was that way...he'd just take dainty little sips. Once the bottles were totally gone, he went about a week where he still didn't drink much, then he suddenly "got it."