quick humble bundle question

I've done both, and the e-mail method is time consuming but feels better, I don't know, it's like you're delivering the game to the winner. But if I do 5+ GAs at a time, I use the keys section (except if the links aren't recognized...)

Up to you I guess!

It's easier to put it into the key section, but more personal to send the key directly. It's really just preference. :)

I've been requesting the key and putting it in the keys section.
But I don't think either way is better - it's up to your preference.

You could create a gift link and send it to their email and screenshot the gift link page in case something goes wrong.
You could put in their email directly to the gift link, but that causes it to get used up and you can't reuse that link for another giveaway if something goes wrong.
You could get the key directly from Humble and put it in the keys section and screenshot the key in Humble in case something goes wrong.
Though things rarely go wrong.

I think I'm just blabbing now.