Provisional there’s a lot of ways to go about balancing that set, but the 3 options I’d consider are taking them all to C9 or just add 3g to the 7, 2g to the 5,6,w to balance the head weights and call it close enough, or glue them as they are and stop thinking. Off the top of my head, I think option 2 gets it close enough you will never notice, but you have this much time invested, don’t let me sway you from doing it the way you want them.
On the ferrules, I have had some that are just too damn tight in the past, I take either sand paper or my hosel cleaning wire brush and run it through the inside of them enough to make a little dust, blow that out and then a q-tip dipped in acetone to melt it back to smooth for sliding purposes, repeat until it’s tight, but you can move it on the tip, grab the hair dryer and get it warm, move into place.