Yes, you can overclock the rom. The best settings are already preloaded. You should be able to push it up to 1ghz. More than that will probably make the device unstable, try at your own risk. All the other settings I recommend keeping them default.
Don't know what to tell you :( As I said, I don't have the liquid anymore, so can't test further. Maybe try to do a clean flash and see if it happens with no additional apps installed. If it doesn't, there might be a problem with one of your apps.
First of all, are you overclocking? If so try without overclocking.
If not: most probable cause is voltage/clock. The rom is undervolted to save battery, the fact that it happens when screen is off (when the frequencies are minimum) makes me think it's an undervolt problem. Try this: use a root-enabled file explorer (ES File Explorer, Root Explorer or similar) to delete the file "/system/etc/init.d/05customvdds" and reboot the phone. See if this fixes the problem.
Sorry, but I didn't test on a Ferrari Liquid because I don't have one. Unfortunately it has some slight hardware differences from the "mainline" version, so there could be problems. Nothing I can do about it at this point, I don't even use the Liquid anymore.
It should work, but not tested. Only change over 4b is the email app is included, you can install it manually from the post above if you want and save you some time. As for KK icons, there are a lot of themes/icon packs in the play store, just install one of them, as long as it's compatible with ADW launcher it should work.
This is either a bug of Google Search or ADW launcher. Try to go in settings --> apps --> all apps, and search for thos two applications. Click on them and chose "uninstall updates" if the option is available, see if that solves it.
You must go in CyanogenMod settings --> Interface (if I remember correctly). There's a section where you can configure the LED color for various apps/actions. Select "Missed Call" and select the appropriate LED color, remembering that "White" will flash the message led and "red" (or "blue" don't remember exactly, just try) will flash the missed call led.