I haven't done this kind of thing in my Character but my opinion about that thing, that kind of freezing is not worth it for F2P .. Since the only source of F2Ps in terms of items and coupons are that Dailies and Events .. If you do that thing and not claim anything, will make you fall behind big time .. Magatamas is one of them, since Ninja Exam gives experience, tons of magatamas per day will be missing to you (30+ magatamas per day or maybe lower) .. And the other items and coupons you will miss with the other missions and events you said ..

If you are active enough to join like 90% of all the sageworld/matsuri events, then sure go level freezing(atleast until you can stack ur pos 1 enough). But if you can't do that then just enjoy the game any way you want :D

But in return you earn advanced runes and seals, and you "earn" coupons by not being plundered so often because of being 15 levels lower than the top players. Though I can't decide if those benefits are worth it in the long run or not.

no, it's not worth it. I'm lvl 100 with over 200k power, my swb servers have 2 brackets and i can be put into either, yesterday during swb I fought a lvl 35. I'm the 2nd strongest person on these servers, the strongest was in the higher tier bracket.

The only advantage of lvl freezing is that u can't be plundered by people like me, but it won't stop other people who also lvl freeze and tbh 1 ss convoy not being plundered while losing the resources from all of the other events just isn't worth it.

so yeah, just level up normaly and get the extra power from it.

F2P and level freezing is a BAD idea. The best thing you could do imo is controlling your level so that you don't over level like skipping plot instances. You could maybe skip ninetails, TI, missions, cat quiz and doing instances that you don't need to slow down further...but I don't really recommend it.

Its not worth it unless you are in a really good and easy cluster where you can competing, it wasnt a bad idea but its worked in the past when new level cap realesed and avoid to level up so if you lucky you were in a super easy cluster or unlucky and just simply drop to harder cluster due to the impact of players number (its happened to me) beside that you didnt level up.

I forgot to mention that I already been freezing for a while so I can rank 2-3 in my bracket now (not 1 yet because there are people with much higher power than me). But I'm nearing the level where I may be put in the higher level bracket. I am asking if it is worth to stop leveling completely or just go on and slowly level up, even though there are 100k players in the next sage bracket.

If you place high in swb regularly you can possibly get 30-60 adv. refines per week. If you enjoy the slow grind and don't mind missing on wanted/nine tails/ti/dailies/sweeping instances then sure (you will miss on 75 coupons, 7 adv. refines, 21 myobokus, main char frags, coins and some power from TI/wanted). Keep in mind what Shadoblaze said though. People quit the game and it's possible that with time your bracket will get merged with higher lvl brackets...

EDIT

Actually, you will miss a bit more power, because you will be unable to fully claim free rewards from events such as fishing mania, time-limited recruitment, great plates etc.