I'm fairly new to this as well but will tell you what we do. Question #1 is yes 18"-30" is fine, shorter equals faster fly action, longer equals slower fly action, try different lengths until you see what works. Question #2 we normally only run spoons off the riggers but you can run flasher/flies. Question #3 50 feet is a little long but might work, we normally do about 20 feet, but try different lengths and see what works. Question #4 we use about an 8 foot leader off a standard dipsy to flasher/flies, any length if using a slide diver. But you need to be able to net the fish with a standard dipsy diver. If you run a meat rig with twinky flies you'll have to shorten to about 4 feet. Question #5 You can run lead core or shorter copper lengths (200-300 feet) off boards, but stick baits is more for spring time. Now I should of stated this is our program for salmon, if your targeting browns or lakers you'll have to ask someone else as we don't target those species.