Yes, LONGHANDS is a Scrabble word!

Letter values in Scrabble US: L 1, O 1, N 1, G 2, H 4, A 1, N 1, D 2, S 1.

Is it a valid word?

LONGHANDS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

rapid handwriting in which letters are set down in full and are cursively connected within words without lifting the writing implement from the paper

Also: running hand, cursive script.