Hi there, it sounds like you have your hands full! especially with the redhead....lol. I have one myself and she is sure different from my son who is NOT red.
I'm not sure about her behaviour issues, but I think you should know about the chest clip issue. It should be tight enough that only one of your fingers can fit in there(not a fist)
AND... my daughter does the same thing with the clip. she will always move it down because she knows darn well, it has to be UP! you have to stand your ground and just say that you're not moving the car, or pull over until it's fixed. OR I've even taken my daughter out of her seat and back into the house until she's ready to put her seatbelt on properly. It takes time and effort. But, you are the boss. and safety is not a choice!
The stopping in the doorway is something I have seen lots of little 2 kids do. It's a game. I worry about the hands thing, but then being the terrible 2s, it could all jsut be a phase. I would take her to a DR if you are concerned, or you can wait and see if she out grows it, but that could take a while.
If she has recently had a new sibling may I suggest you try giving her more attention as more often than not Behavioral issues pop up when a new Baby arrives , I note you said you had noticed it 'lately'Most of what you describe could be put down to old fashioned Jealousy , before big evaluations how about you give her one to one attention, and lots of Games and Fun so she doesnt feel left out ,With some of the behavior patterns have you particularly made any fuss about them that she could have picked up on and decided it gets her a lot of attention so she does it more, check these things out ,then go for Help if you have to , however go online and make sure you know what form the help will take.
The only behavior, out of ALL of them (and there are a lot!) that truly points directly at OCD is her problem with doorways. That's classic OCD. Rituals entering and exiting doorways point directly at OCD - where the rest, taken alone, could look like extreme controlling/manipulative behavior.
I agree with jd. Get her to the doc - the sooner the therapy, the better, if she needs therapy.
OCD is an anxiety disorder. Anxiety is an inherited trait. It is highly likely that some of your children will inherit some form of anxiety. Perhaps you should contact your pediatrician for more information and advice re anxiety. And yes, one can notice traits at birth. Many of the behaviours you are describing are those of anxiety but you will need confirmation from your doctor. Two points - children do not outgrow anxiety nor will it go away but anxiety is highly treatable and manageable. The second - the earlier the diagnosis; the better the prognosis. I wish you the best ....