The pirate
Piece 7 makes a nonogram when the numbers are moved outside of the grid. This has two possible solutions (either A or B cells are black).
In the top left corner of the envelope, there's a hint that black means 3, white means 2 and green means 1. These numbers form a slitherlink puzzle.
Piece 5 appears to have a part of the loop already filled in. However, this doesn't fit the numbers as is, which is where I got stuck. However, LeppyR64 figured out how to fit everything together: turn piece 5 90 degrees clockwise.
Looking at the pictures, the pirate cannot cross the slitherlink and only takes letters on which he steps with his good leg. So let's pick every second square only:
Taking the corresponding letters from piece 1 gives QGOBMDUDQDW.
The roller
The clues from piece 6 fit the crossword on piece 3. Right-side-up clues go across, topmost first:
Tight (4) = ROPE
Lincoln (3) = ABE
Speeded (4) = SPED
??? (5) = SWEAR
Twinkle (4) = STAR
Panda (2) God (4) = PO / LOKI
Twins (5) = OLSEN1
Upside-down clues go down, rightmost first:
Destroy (4) = RUIN
Greenpeace (4) = PETA
Cupid (4) = EROS
Abbacy (7) = REDWALL1
Superior (4) = BEST
Circle (3) Thus (2) = LAP / SO
Number (2) = PI
1 Found by M Oehm in the comments.
Again, piece 1 displays the start and end squares of the maze. This one is solved by making chess-style knight moves on the free squares. (OP acknowledged in the comments that the final square was blocked by accident.)
Taking the visited letters from piece 1 gives us QQAWPLDPALW.
The pirate
Piece 7 makes a nonogram when the numbers are moved outside of the grid. This has two possible solutions (either A or B cells are black).
In the top left corner of the envelope, there's a hint that black means 3, white means 2 and green means 1. These numbers form a slitherlink puzzle.
Piece 5 appears to have a part of the loop already filled in. However, this doesn't fit the numbers as is, which is where I got stuck. However, LeppyR64 figured out how to fit everything together: turn piece 5 90 degrees clockwise.
Looking at the pictures, the pirate cannot cross the slitherlink and only takes letters on which he steps with his good leg. So let's pick every second square only:
Taking the corresponding letters from piece 1 gives QGOBMDUDQDW.
So the final clue is
11+? 11+? 11+? = 33. We have the 11-letter sequences QABMLLWJCOWQGOBMDUDQDW, QQAWPLDPALWQABMLLWJCOW and QGOBMDUDQDWQQAWPLDPALW. By rotating letters by a number of positions we get:
QGOBMDUDQDW, rotate by 1 -> RHPCNEVEREX
QABMLLWJCOW, rotate by 18 -> ISTEDDOBUGO
QQAWPLDPALW, rotate by 15 -> FFPLEASEPAL
