@neonthewrite– Regarding the lighter, the older sprites most likely reacted a lot like Bowman did. Amazed and wary, and surprised that he can hold even a small fire in his hand. Since he’s the expert with it, they’d most likely leave it to him simply out of fear of accidentally setting it off themselves (they really really don’t like fire).
@nightmares06– Sam does have his climbing abilities, only with the sprites he doesn’t have the standard hook and thread to climb with. Trees have fairly thick bark which offers plenty of handholds, so when he was bored, he would try climbing up the tree trunk. It gave him something to occupy himself with when Bowman finally got himself off the ground and flitted off, and went too far to hear Sam cheering him on.
Dean taught Sam caution with everything he entrusted his little brother with, so Sam knows the proper handling of a lighter (and a gun, though he didn’t get cursed with a gun). He won’t leave it lying around again, and along with many of the other items he was cursed with, it serves as an anchor to his old life to hang on to.