T.S.
R.,
You just described our 21 month old son, Ryan - almost exactly.
1) Picky eater. Ryan used to eat EVERYTHING we gave him. Now, there are times he only eats yogurt or fruit. We're having a problem with him wanting cookies ALL the time. No, we don't give them to him all the time, but they were an after dinner treat. NOW, he will scream and point to the cookie to eat instead of dinner. When he does this, we remove him from the table until he's ready to eat. Just keep offering the food you make for the rest of the family. If he's hungry, he'll eat.
2) Night waking. No, it doesn't sound like terrors at all. Ryan had them for a short time and they were horrible. He was uncontrollable and couldn't be soothed. Luckily, they seemed to have passed. But, he still wakes up at night (did last night, actually). If he's moaning, we let him moan. If it turns to a screaming fit, I will go in there and try to comfort him IN the crib. We've learned the hard way not to take him out. All you do by taking him out of the crib is condition him to scream in the middle of the night to get the attention he wants. And TV is stimulating, so I'd cut that habit out right away.
What has helped Ryan with self soothing is leaving a sippy cup of water in his crib for him to drink when he wakes up. Also, we have a CD player playing music under his crib and recently put an air purifier in his room (white noise). Since that, he's slept through a lot better (last night was the first night he didn't sleep through since we got it).
3) Diaper. I think he's just pushing his will on you and Dad. We usually sing ABC's, Itsy Bitsy Spider or another favorite while we change Ryan. Sometimes it helps, but other times it's a challenge. Just go as fast as you can.
4) Throwing. Oh. My. Gosh. Ryan is HORRIBLE with this. We're still trying to deal with this issue. Whenever he doesn't get his way (like a cookie), he will pick up whatever is closest to him and will throw it and look at us like, "HA!". We have wood floors, so things make a loud noise which gives him even more satisfaction. At first, I was ignoring it, but it didn't seem to work. He would just keep throwing and throwing...he even tries to throw the dining room chairs. So, what we've started doing is putting him in his (carpeted) bedroom. He can throw all of his toys and we tell him he can come out when he's ready to be nice. We don't lock him in or punish him. He has the choice to come out when he's done throwing. Oh, and he has to clean up the toys - with our help. As he gets older, we will take away any toys that are thrown. That worked wonders with our older son.
Seriously, you aren't doing anything wrong. It's so typical as toddlers crave independence and want what they want, when they want it. Just find what works the best and be consistent with it. If you give in once, it's like 3 steps back. You and your hubbby have to be on the same page and enforce the same rules. My husband and I often talk after the boys are in bed about different ways to handle the behavior issues that come up. We kinda keep each other in check with different ideas or perhaps different approaches to what may work.
Good luck and hang in there! These phases will pass and then you'll be on to something else. Lol.
T.