I run 8# mono to a small swivel to 8-12 feet of 6# Seagar floro leader. It made a huge difference for me over just 8# mono all the way to the lure.
I only use flashers as I go deeper after the first 2 months of the season. I do use them with my chamberlain release but had to get creative. I run my DR cable to the top of the chamberlain then have a 2-3 feet section of light chain that connects the bottom of my chamberlain to my DR ball and the flasher off the ball. The chain gives me the seperation I need from the flasher to the lure. When using vertical flashers, I can use this in place of the chain.
I like that 100 foot rule mentioned above. I have always just put my lure back 85-105 feet when not using flashers.
I also agree that you should stay with the leadcore. Over the years, leadcore has outfished DRs 5-1. Since you have oversized rods, you can use the Offshore inline planer boards to pull the LC rigs out from the boat and cover more water. Plus the planer boards give even more action to your bait. It does take some experience to pick up light strikes on the boards though. I am thinking of going to a mast this year though just for the convenience and so I can run 4 LC setups or 2 LCs and 2 fly rods off the planers.