1) I've read the manga twice and I've never seen this picture anywhere in it...maybe it's an extra that Hiro wrote or something?
2)Haha! Found it! It's an Omake that Hiro wrote after chapter 68. If you go to Mangareader this picture is in chapter 68 page 40, right as the boys come storming in to help the girls get rid of the Phantom academy thugs. Found one! Onto the other two(still haven't seen the first picture though...) By the way, a whole episode of the anime series of this particular short comic came out just a day ago, it's called Fairy Tail OVA 2: Yousei Gakuen Yankee-kun to Yankee-chan. It's a good one, you should watch it!(by the way if you want to read just the comic short it starts on page 22 of chapter 68: Fairy Academy Omake)
3)I'm not sure which chapter or page, but it's somewhere towards the end of the edolas arc. You can tell it's edolas from their outfits, and since it's a while before all 3 of them meet up there it's probably towards the end...I'll let you know if I find it! -goes to read manga-
All I can remember about number one is that they were doing some amusement park, and Natsu also had a pool of fire, or something like that. Sorry! I have terrible memory!
For the one where Gray was freezing the swimming pool with Lucy in it...I think it was a special, which I saw on utube, and I'm not sure about the 2nd one which I am really sure that it's not in the manga, and I not sure about the 3rd one although I have seen it before
