1.Be excited about=be excited at 对...感到兴奋,激动
Why should we be excited about the 2008 Olympics/the 2010 World Cup?
I was excited about a job interview.我对那个面试老激动了,当时.
2.be interested in是对什么东西对人很感兴趣.其主语应该是人或其他有生命的东西.如：I'm interested in you.我对你很感兴趣.The ants are interested in sugar.蚂蚁对糖很感兴趣.（蚂蚁很喜欢糖）
be interesting in应该是错的,后面的in不要吧,be interesting是指什么东西或谁很有意思,是其本身的性质,主语可以是人,也可以是物.如：You are interesting.你很有意思.The book is interesting.这本书很有意思.be exciting也没有这个用法.