Each of the cards has the same beginning:

Special: Add 1 misfortune to the dice pool for each target. Add 1 recharge token for every 3 fa our spent. You may continue to spend da our to add recharge tokens to this card as a manoeuvre while it is recharging.

1) How does someone with Favour between 3 and 5 get this blessing to last longer than their own turn? At that level, they'll add 1 recharge token, which gets removed at the end of their turn, ending the blessing. Keep in mind that Favour is generated AFTER invoking a blessing, and that if you have enough Favour to activate the blessing, it automatically goes off, meaning you couldn't then try currying more Favour. So someone with a willpower of 3-5 won't be able to use this blessing unless they're below threshold and get to curry more Favour before the blessing goes off or are pretty far above threshold.

2) assuming you've gotten this blessing to last longer than your own turn, how much Favour do you have to spend with the manoeuvre to gain an extra refresh? Is it 3 Favour, or just 1? If the former, how do you get that much extra Favour without using Curry Favour? If the latter, then it wouldn't make sense to put more than 2 recharge on the card at the start and then just keep adding one to it each turn for 1 Favour.

So how on earth do these cards get handled? Should Curry Favour be allowed so long as this spell is recharging? If so, can one curry Favour while also singing (the Chanty cards say you are singing the entire time they're active)? Would you allow a player to quick cast the curry Favour action in turns after the blessing is active, or would it take up their entire action for the turn, as well as using the maneuver to add the Favour? That seems like he most logical way to do it...

Edit: for that matter, should a player be allowed to hold off on activating this blessing until they have as much Favour as they want, or will it automatically go off when they have the minimum of 3? Seems to me like the former would be more useful...

I'd say the easiest solution is that the player invoking the blessing can decide (before casting the blessing) how many favour the blessing needs. So the player could choose 3, 6, 9 ... and so on. The blessing would not be invoked until reaching that goal and that would allow the use of Curry Favor and give the blessing more turns.

That is not stated outright, but it's how I feel this was intended. Otherwise you'd need WP 6 to use those blessings to any effect. And Chanty of the Wind or Water Walking would be all but impossible to use for anyone.