itch.io

1) opposite of (to) "contract" (verb), 6 letters 
2) As you've seen with a previous grid puzzle, 26 letters + 10 digits fit nicely into a 6x6. But 26 letters don't fit nicely into a 5x5. So you kind of have to. squeeze it. So every cell is one of 2 letters. the 9th cell shown, is either I or J. So for a 4 cell word, write down those 4 cells (4 letter pairs), and make a 4-letter word out of them. 
3) Rotate puzzle actually shows both correct solutions at once. Note that there aren't that many vowels, and you need at least a couple per word. (hint: try making a word starting with the central S)