[okayama]

1st scramble: F2 L' B2 L' B2 R' F2 L2 B2 D2 R B R2 U L2 U2 R2 D F' R' D'
1st solution (1-hour): B R' B U' B2 U' B2 R' L' D2 L U2 L' D2 L U R2 U' B' U' R U' F D' U' R L' U' (28 moves)

Spoiler (Click to View)

(Inverse)
Pre-scramble: R

2x2x2 block: U L R' U D F'
2x2x3 block: U R' [@1] U B U R'
More square: R' U * R B2
More square: U
All but 3 corners: B2 U B' R B' R'
Correction: R

Insert at *: U2 L' D2 L U2 L' D2 L

IF says the optimal insertion is

Insert at [@1]: R2 U B' U' B R2 B' U B U'

which gives 27 moves.

2nd scramble: D2 U2 F2 R2 D2 B D2 F D2 F U' R' F' R' B2 F2 U L U' B
2nd solution (1-hour): U2 B U' B' L' D L U2 L' D' L R U R' F R F U' R U B' L B' D2 F2 (25 moves)

Spoiler (Click to View)

20 min solution.

(Inverse)

2x2x2 block: F2 D2 B L' B
2x2x3 block: U' R' U F' R' F'
F2L minus 1 slot: R U' R'
All but 3 corners: U2 * B U B' U2

Insert at *: U2 L' D L U2 L' D' L

Quite a nice scramble, many nice starts were found on inverse.
I also found Sébastien's 25-move solution (after I found the solution above).

3rd scramble: F2 L2 B2 D R' F' B2 D L' U R2 B2 D2 L2 D F2 U D B2
3rd solution (1-hour): D2 R L2 B2 D L' U F' U L F U2 F2 L' B L F L' B' U2 R U2 R' U2 L' (25 moves)

Spoiler (Click to View)

15 min solution.

Pre-scramble: L2

2x2x1 block: D2 R
2x2x2 block: L2 B2 D
2x2x3 block: L' U F' U L
F2L minus 1 slot: F U2 F' *
All but 3 corners: L' U2 R U2 R' U2 L
Correction: L2

Insert at *: F' L' B L F L' B' L

Nice scramble again, I also found nice starts on inverse:

Pre-scramble: R

2x2x3 block + EO: F2 B2 L' U R2 F' R2 B L'

or,

Pre-scramble: B2 D R

F2L minus 1 slot: F2 B2 L' U R2 F' R2 L' D2 B (+ B D B')

but I couldn't find any good continuation.