As a veteran habbo player, there are no cheats. No ways to get furni, credits/gold, etc. The only thing that can be done is some light scripting involving packet sending which will do things like give you random rights to a room, glitch teleports, etc.
Everything is now serverside and Sulake don't play with people that hack their servers (more prone to be detected due to the nature of everything being bought with real life money).
probably not what you wanna hear but free servers are pretty fun if you find one you like and they usually start you with bookoo creds and some perks just throwin it out there
that's too bad!
i remember that a few years ago there were glitches you could take advantage of but I can't actually remember and its probably fixed nowadays ;_;
(habbo is nostalgic tho)