As I said, I got mine a long time ago. WTF was just changed to WT in 2017, so I wasn't aware. Our competitions followed WT style and we competed with Taegeuk forms.Welcome to MartialTalk. You might consider going over to the Meet & Greet and tell us about yourself.
There is no such thing as WTF style. Which also no longer exists, having changed their name to WT. WT has no schools, no curriculum, and awards no rank. It is a sports governing body for Olympic-style competition. No more, no less.
Also not true. KKW certification is something like $100. That's comparatively inexpensive.
Again, nope. The KKW has specific curriculum requirements, but they are not at all tough. That is one reason why there are so many baby black belts in the KKW system.
For that matter, although the KKW "requires" the taegeuk poomse, there is zero enforcement, and there are tons of KKW black belts who don't know anything at all about the taegeuk forms.
More accurately, it's a one time fee for each rank. You pay for 1st Dan. And again for 2nd Dan. etc.
And this is true of every rank in every school in every system I ever heard of. Rank doesn't expire.
At several schools I went to, they offered Kukkiwon certifications or other certifications, and in my experience, those other ones were always cheaper... Partially because the Kukkiwon ones required sending paperwork to Korea [the certifications have seals and signatures on them that must be done in-person], and there were a lot of fees associated with that. I'd be surprised if they were cheaper than other certifications, but things might have changed since I was looking into it. Even back then though, it wasn't ridiculously expensive and worth the few extra bucks.
In terms of the curriculum, I know for second dan, the bare minimum requirements were absolutely brutal, and my school was pretty strict about it. First dan wasn't nearly as bad so a lot of people can get through that one, but it's gotta get stricter as you go up the dans or we'd have 4th dans all over the place. I imagine this is probably regulated based on an integrity system, and lots of money-focused or well-intentioned upper ranks may let A LOT slide. However, a master of high reputation/rank is probably going to be stricter overseeing these exams to maintain his reputation. Mine was a 8th dan from the Korean military, so I imagine he didn't let a lot slide as others do.
Yes, pardon me. I should've clarified there's a fee for each dan. You shouldn't ever have to pay for your 1st dan again even if you switch schools. But yes, I've never heard of that being done any other way, except if you do not have a Kukkiwon certification and you switch schools, they may make you re-test for 1st dan based on their certification/testing system.