Riding with the chirping is okay, it shouldn't hurt anything. But, at least tighten the 3 Philips screws holding the choke (enrichener) assembly that is accessible. You might get lucky, and that will be the one that needs tightening. If that doesn't help, then you will have to remove the carbs so that you can access the other choke assembly. I 99.99 percent guarantee that is the source of the chirping.
Your highway hesitation needs more description to diagnose (like what year carbs, for starters, but I assume from the chirping that they are BS38s). If it happens during acceleration, you probably need re-jetting due to the pods and exhaust mods that you did but never re-jetted for. If it happens at steady throttle, maybe your tank is poorly vented.