Oh T., I am right there with you. I have a 2 1/2 year old little boy, and everything you said is my son to a "T". He is an absolute handful, and everyone around us knows it. I just had a baby in April, and that was pretty rough on me with him being so "high maintenance". I guess my advice, and what I have started doing with him, is cutting him off. The whining absolutely drives me nuts, but I've realized that I'm going to have to listen to it, or I end up giving in and it's a never ending battle. When it comes to food, the minute he gets in the car from me picking him up at daycare it starts; mommy I want ...... and it could be cereal, waffles, whatever. I say no mommy is making this for dinner, and of course here comes the whining, screaming, throwing stuff. We get home and he keeps trying mommy I want bla bla bla. Well what I've started to do, (because I was getting to the point of constantly yelling just to over talk him and it just made the situation much more stressful) I just tell him this is what I'm making, when he doesn't take his plate and sit down to eat, I go about my business and within 5 minutes the kid is sitting down at the table eating quiet as can be. I think at this age, they are REALLLY testing their boundaries, to see how far they can push us. Well he would push me and I would just give in because it's easier. Then on the days where I wouldn't give in, it was like WWIII, because he had a total melt down, he's in and out of time out. I've figured out that I have to be consistent with my rules, because he is not dumb by any means, and remembers if I gave in on something the day before. My child is like a well oiled machine, he does not like change, likes things to be the same every day.
The sleeping, we are still going through that with him. He's been in his big boy bed since January. This week is a good week for sleeping. He's in bed between 8 and 815, and I wake him up about 6 and he is a little grumpy at first, but then after I just walk away for a minute from him and let him wake up he's usually fine. Last week wasn't a good week. He was up every night around 2 or 3 and in my bed. Or he would wake up at 430 ready to go for the day. That's just an ongoing thing, and I just keep putting him back in his bed and try to keep his nighttime routine the same every night.
Yes, they definitely feel your energy, I was exhausted this weekend, and very short with the kids, and he was a total brat all weekend. I sincerely believe it was because of my mood, that he was being a brat.
I guess my advice is be CONSISTENT and realize that they are pushing every boundary they can. Don't think your alone, because I am right there with you. I have a 12 year old step-son that lives with us, my 2 year old son, a 4 1/2 month old baby girl, and my husband travels for a living and I work full time. So I completely understand your frustration with this. It is such a fun age, but boy they can push you to the end.
Sorry so long....
:)