I've never experienced any of those issues in my 2+ years with Android. I've always used stock Android (on the MyTouch 3G and then the Nexus One) -- I think you must be using a buggy build.
It's very eerie when you click the phone app to make a call and it freezes for a second, then half the app is drawn, you shake it a bit and it sometimes comes back, but then the call doesn't go through. Then you go to send a text and it won't load your messages or the keyboard doesn't show, or it pops up but you can't see any keys, or you see the keys but when you type nothing shows up until you close the keyboard, or it takes two seconds before what you typed shows up. All these are symptoms that you need to restart.