I have NO idea really if any of this will work in the long run. We are "thick in it" too. Taylor is 3 yrs 6 mo.
: My cousin's daughter is 3yr7mo and exactly the same too. We agree it must be a "phase". Sigh.
I am currently reading "1-2-3 Magic" and some of what that book suggests seems good. "Time out" and "Go to your room" seem to sort of work for Taylor, but only sort of. We're changing it a bit. We only send Taylor to "time out" for really really bad bad things. Hitting. Spitting. Etc. When he gets really going with an out of control tantrum [or I see one coming] is the only time we send him to his room "to calm down" and I tell him [and sometimes quietly 'escort' him] to go to his room until he has calmed down and wants to talk/ be nice/ etc. He usually does after a few minutes. On a few occasions though he has been hysterical so I sit on his bed and rock him until he calms down and then I tell him he can play quietly until he is ready etc. This too seems to work most of the time.
As for the whining, wheedling, late for everything, blah blah blah.
"Time out" etc doesnt work for us. That book calls that stuff "start" behavior. In other words you want a child to "start" something. ["Stop" behavior is where you want a stop doing that, go to your room sort of thing.] Per book, THAT is much tougher. Duh.
: We've been trying alot of "big kid" redirection and "games". I am IN LOVE with the kitchen timer. [I think it is becoming my new best friend!] I set the timer for 1, 2, or 3 minutes. If Taylor does "what ever" before the buzzer he get some reward. If not, no reward AND then he is treated like a little kid and *I* do what ever. This is working well for him right now. Figuring out the reward is tricky though. And it seems to change often. Uhg. We do stuff like "give dog/cat treat" "pick own clothes" "pick book/movie" as well as candy, cookie, snack, treat and Go to park, McDs, beach, friend's house, etc. For example if he isnt "agreeable" in grocery we dont go to park.
I am doing much better at this than my husband though. It drives ME nuts the way our son eggs hubby on!! I want to just scream sometimes. Especially meals. We've started putting each other in time outs and such though. Since we are both ok with it it sort of works. And of course Taylor loves it!! For example if he yells at me and I yell back we BOTH do a time out. [In our house yelling is a BIG no-no FYI] And I've been using the timer for "sharing" between kids. And if Taylor hits back both kids go in time out.
Ooh! One last idea that worked recently. Cleaning his room!! If Taylor has a BIG want [and he gets it] he has to do a BIG what ever. So we've started a chore chart and if he cleans his room [with help] every day [or most days anyway] whithout whining [much] then he gets a dollar on Monday to save or spend. Amazingly he went SIX weeks this summer before spending his dollars on a new baseball bat and mit!! [We took him to a minor league game too, we were SO proud!!] I though 3 was a bit young for a chore chart, but we used pictures instead of words on most of it and stickers etc. And we use "good enough" instead of "perfect" too.