Thanks for playing! what exactly do you mean by "slowish"? since it's a turn based game, you can decide the speed you play it yourself :-) do you have any ideas on how the perceived speed could be increased by means of game mechanics?
the fact that the pieces are only usable on the board you put them first has been intended, in order to prevent a playstyle where players would simple put their whole inventory on each board, and brute-force their way through the levels... but maybe there are other ways to handle this problem as well.