You don't need to replace the ignition key when you replace the switch. The switch is a separate part from the lock, and I was able to remove the switch from my lock in a parking lot in Virginia to get to the bottom of the same problem you are having. I ended up driving home to New Jersey using clip leads to short the switch contacts, and immediately replaced the switch (not the lock) when I got home. No problems ever since.
As for your LED signals, you can't use the original flasher unit because it needs a certain amount of current to function and the LEDs don't provide that. You need to get an electronic flasher which is load independent. I got mine from Pep Boys but any FLAPS should carry them.
As for your clock, in the past decade I have upgraded thousands of them for customers around the world. Contact me directly for more information.