Aho and baka mean idiot/fool etc. Also kimi isn't really polite, if you call someone older than you or someone you don't know kimi they might get annoyed. As for crazy, try something like 変（へん）、　おかしい、　頭（あたま）がおかしい 、　変わった人（From 変わる（かわる））　if thats the meaning of crazy you mean. Use like 変な人　/　変なやつ / 　あいつは頭がおかしい or whatever. Actually maybe it's better not to use any of these...

Hello Cristine, In Hyoujungo the meaning is 'Baka', and in Oosaka dialect is 'Aho'. To Tokyo people, Aho is a little heavy word because Aho imply the meaning of a little low intelligence. In casual scene Tokyo people say [ kimi ha baka janaino?] on the other hand, Oosaka say [omae wa aho ka?]. In Japan, the polite word is kimi rather than omae.