Is there hard-water deposits inside the pipes in my house?
Faucets have screens on them.  Your pipes shouldn't have deposits on them because the sediment will build-up on the bottom of the tank when it is being heated (the change in temperature and stagnation are the main reasons for the sediment falling out of solution -- neither of which happens in pipes,) and it shouldn't go out of the top.  The screens on the faucets are to stop debris that are lighter than water.

That's not to say that it's impossible for pipes to get build-up, but you'd have major water heater problems prior to your pipes getting clogged.  Clean the screens to see if the flow rate / pressure goes up.  If it clears up the problems, no need to mess with the pipes!  

(Also, another way to test whether it is merely the screens giving you the problems is to test it using the cold water.  If the cold water is also slow, it's the screen on the faucet, not scale build-up in your pipes.)