For the crew skills issue, just remove 'Onslaught Crafting' (set max crew skill to 700 for everyone and remove the skill from trainers), then run an update that checks actual crew skill, and if equal to or greater than 600, sets actual to 700.
Either that or just come out and say the 'bug' was allowing people to access 700 without buying the 'Onslaught Crafting' , re-impose the fee, and set every crew skill for which the training has not been purchased back to 600.
At this point, I've already bought the skills on multiple characters - both back when it was required, and now because of the incompetence your team has shown in fixing the issue (I don't have months to wait while you keep screwing up the fix by not actually fixing anything such that my characters cannot use crew skills above 600 they previous could access).
So just stop trying to fix it while trying to re-impose the fee - remove 'Onslaught Crafting', set everyone at or above 600 to 700, and move on.
All your current efforts are just a giant waste of time - both of yours and ours.