I am still getting used to parking the Prius as a new owner. However, when I get out of the car and determine I have to move 3 inches forward or backwards in my garage, it is very difficult. I am experiencing grabby brakes - OK. I am seeing threads on this. The other thing I am experiencing, even when the car is in EV mode, is that the electric motors seems too eager to go. As soon as I lift the foot of the brakes, the car wants to lunge forwards and backwards (depending on which gear I chose). I wish there was a way to slow down the electric motor's urge to go. It is all in the electronics because it is not as if the motors have an idle like a regular car. The feeling is like if a regular car, with automatic transmission, is set with the idle too high so that as soon as the brake is released, the car wants to go forwards or backwards. This is especially bad if I am backing down an incline. The incline is pushing me back. The electric motor is pushing me back. The brakes are grabby. There is no gentle release of the brakes. As soon as the brakes are released, I am accelerating faster than I wanted to go, I step on the brakes and come to a quick halt. My only solution is to shift into N and glide down. I love the Prius - it has its rough edges but the fuel economy is incredible. I got 51 mpg without trying on my commute in today - and I am still in my first 1000 miles of ownership. I expect to improve upon this after my first oil change at 5000 miles.
Every concern you have is normal in respect to the Prius. You, as all of us have that switched from a normal gasoline engined car to the Prius will get use to all these quirks the longer you own the car.
I am not experiencing what you are experiencing. When I pull up to a stop light, it almost feels like I could pull my foot off the brake and I'd just sit there. Same for backing out of the garage. I have to depress the pedal to go. Does this change for you if you select different running modes, as they tend to change the sensitivity of the pedal movement?
As for the "adjust 3 inches forward or backward" problem, here are some tips I've been using: 1. I measured from the front of the car to the base of the windshield and it is about 3 feet. So that helps me judge. (or maybe it is 3 feet from bumper to where I sit... guess I'll have to check that again) 2. In the garage, I put a piece of tape on the wall in front of the car. I used to stop my old car when the front of the hood started to block the tape from my view, but I can't see the Prius hood at all. So when I get in the garage, I lean forward as much as I can and then I can see the flat part of the hood at the base of the windshield. When the leading edge of that flat spot reaches the tape, I stop. It's worked well so far.
Back to the OP's original post about the high idle, I am not having this problem. When I put mine in either R or D and let off of the brake, the car moves ever so slowly. Very much like any other non-hybrid car I have ever owned.
Coming from a manual transmission, I definitely feel that the creeping torque from the motor is too high. We're used to slipping a clutch to feed in a small amount of torque in order to creep. There have been frequent questions on the UK mailing list asking whether it's possible to turn off creep entirely. (HTMLSpinner's right about the engine idle speed being 1,200rpm but that's irrelevant when creeping, because that's done entirely by the motor - the [Gen 2] engine can produce at most 80 N*m of torque at 1,200rpm, and it's not multiplied up as a traditional transmission would do.)
I used to have an old front motorcycle tire against the wall at the back of my garage to park my truck and Cadillac. They were both long. When I saw the tire more, I backed up a little.
I'm getting used to the grabby brakes, you will too. I'm sure its just one of the prius quirks. They really should have implemented a brake by wire with a good pedal feel. On the fast creeping, I don't feel it on mine. It is a little faster than a normal car but not hard to control. I would really see if you could drive another at the dealer to see if it is really fast. If it is get it fixed. On reverse on an incline I do have my foot on the brake with light pressure. Good luck. I have 600 miles on mine.