Yup. Sure can. You quoted all relevant rules which state that you can.
Simply put, you can use your single swift action whenever you can make a free action. You can use a free action during any other action. Ergo, you can use a swift action during any other action.
This is no different from a paladin moving 15', performing a Smite Evil as a swift action, and then moving te other 15'.
Your example seems like a cool tactic that I'll start employing. Its a great way to step into range and then step back out. Perhaps I need to step into to touch someone (like healing an ally) and then step back away from danger.
Yup. Sure can. You quoted all relevant rules which state that you can.
Simply put, you can use your single swift action whenever you can make a free action. You can use a free action during any other action. Ergo, you can use a swift action during any other action.
This is no different from a paladin moving 15', performing a Smite Evil as a swift action, and then moving te other 15'.
Your example seems like a cool tactic that I'll start employing. Its a great way to step into range and then step back out. Perhaps I need to step into to touch someone (like healing an ally) and then step back away from danger.
It's also a fantastic way to spam True Strike on a charge for when you absolutely, positively HAVE to hit something.
Or taking a Withdraw Action and still getting off a Fireball.
Yes as long as you are not taking an action that restricts it.
As an example if you are doing an action that takes two hands then you can't cast the quickened spell if it requires a free hand, but otherwise feel free to use that swift action.