using RAND in a query is VERY intensive. its not the number of queries that you need to be concerned with, its what each query is actually doing. 1 HEAVY query (like doing a RAND against 1000's of items) is worse than multi properly indexed queries.
Its not so bad when you don't have A LOT of items. I guess I could look into adding it and just add a note saying that it is a very intensive process and could slow load times down.. ie, use at your own discretion.