Ok, 20 run trials on lvl 1 easy destiny tiles result:

Numbers for Destiny, Labyrinth lvl1 easy.

Tiles: 197

Runs: 20

Lose 4 moves: 10
Lose 3 moves: 14
Lose 2 moves: 9
Lose 1 moves: 11
Gain 1 move: 22
Gain 2 moves: 11
Gain 3 moves: 25
Gain 4 moves: 25
Sent back: 30
Move twice: 15
Reveal Grids: 25

It looks like people's hunches are technically right about losing vs gaining moves (around 22.33% chance of losing moves vs 42.13% of gaining). Around a third (35% from the raw numbers) of the time though it's something that isn't gaining or losing moves, and around 42.8% of that is sending back to where you came from and that tile becomes blocked, which is a bad thing most of the time as you lose 1 move + gets shoved back into a space you most likely don't want to go.

Destiny tiles don't like 2 moves (losing or gaining). Funny that.

Overall, though, "bad stuff" happens (losing moves + sending back) is around 37.6%, while "good stuff" is around 62.4%. May crunch out an estimate of errors later (or someone with better statistical knowledge can do that for me? :P).

All in all I'd say that is hard proof that odds for destiny tiles are pretty good in lvl 1 easy.

Notes: I've also included data from destinies triggered by "repeat third last event" tile, with the assumption that the repeat repeats the even of the tile but not what happens, and thus essentially another destiny tile.