"STOP RIGHT THERE CRIMINAL SCUM!" Is practically at meme status now. XD
I kind of like "Halt! Halt! Halt! Halt! Halt! Halt!" myself, but that one works too.
But yes, I'd say the crime system could do with some improvement. For one thing, NPCs should not go screaming Thief! No! Thief!" if you just pick up that strawberry you knocked over, in terms of how the grab button, which I assume will remain in the game, works with the crime system, I think Bethesda should draw inspiration from the mod Put It In Its Place for Oblivion, which makes it so NPCs don't immediately assume you're stealing something if you grab it, as well as adding other features, and the psychic guards do need to go, as well as the psychic merchants who knew that the strawberry you stole from someone's house on the other side of Cyrodiil was stolen. In general, I would say you should only get a bounty for crimes if someone was able to report you, if people see you commit a crime, they should go to report it to the guards. This could potentially allow players to avoid their crimes being reported by killing any witnesses, I'd say there should also be an option to bribe witnesses or maybe even intimidate them into not reporting your crime. After all, I think that having a big orc wearing Daedric armor and carrying a heavy warhammer tell you that it would be rather unwise to report his crimes would make one feel less inclined to do so. The difficulty of succeeding at these things should depend on certain factors like the player's skills and attributes to avoid players being able to always escape from crimes just by pursuading witnesses not to report them. I would also say that NPCs should be able to forgive minor crimes, depending on their disposition towards you, because it would seem reasonable that a close friend to you would not report you taking a piece of bread, they could just berate you for it and take it back from you, or even not do anything about it at all, though if you keep doing it repeatedly, I'd say it should still reduce their disposition or maybe even make them report it. Obviously, serious crimes like murder or assault should still be reported.
I would also say that guards should respond better to suspicious things like finding a body on the ground or seeing you sneaking around, if they find bodies on the ground, they should get suspicious and start to look around for the killer, and they shouldn't react like this to people they killed themselves. It was kind of absurd in Oblivion when NPCs would kneel behind bodies killed by them and say "The body is still warm, the killer must be nearby." I guess Imperial guards have a very bad short-term memory. And if they see you sneaking around, they should start to watch you and maybe follow you around. When you get down to it, someone sneaking around WOULD look kind of suspicious.
The idea of a regional bounty system does sound like it would have some potential, especially if combined with a system that allows your bounty to reduce over time if you can avoid the guards for long enough, this way, aside from turning yourself in or having the Thieves Guild take care of it. You could have a third option to deal with your bounty which would be to go to another region and lay low for some time, obviously, the higher your bounty, the longer it should take for it to go away.