the 어요 ending is the polite version of the 습니다 formal ending. the two sentances are the same, just used in different company. basically strangers vs acquaintances... but its more in depth than that.
Because 재미 isn't a verb. The verb here is 없다 (to not have). 재미 is a noun meang fun or interest, so 재미 없습니다 means "to not have fun/interest," in other words, "it's boring/uninteresting"