Here's my thoughts on two items that have come up.
First ... practice weights. I can only relate this to weapons training. You always, and I mean ALWAYS train with heavier weights than you plan to swing. Chop at sturdier targets than you plan to hit. For your purpose, the heaviest fly you plan on throwing at Musky and Pike ... that, at least, is what you practice with. Then you'll know the characteristics of the heaviest, and everything lighter will stay above your head. Just remember, you throw the line, not the fly. Flies that are more resistant to airflow change your cast more than heavier weight flies. Heavier just hits you, air resistance slows the line down.
Second ... You mentioned that you don't use the floating line much. I am not speaking from experience, just from what I've seen and read. Most Pike and Musky fishing is done near the surface. Shallow water, big flies and usually, fast retrieves. Distance and depth aren't required as much as covering water quickly. Fan casting short distances is how I understand it. They aren't spooky, they chase any commotion near the surface.
I truly hope you get your trip, and it's an experience of a lifetime.