we dont have a word equivalent to it, most of the time if we refer to non human things we just say the name of the thing.we dont usually say "he eat it" "dia makan itu", as "itu" is highly ambiguous, we usually just say what he ate. this may cause confusion in translating "it" into indonesian. so "it" is usually translated as ini (this), itu (that), and those words has positional information, unlike "it", as far as i know there are not any indonesian word with the exact same meaning as "it", itu and ini came the closest to it.
no, it's perfectly normal, but as "ini" gives a sense of position similar to 'this', the object that you refer to as "it" must be close to you, you cant use "apakah ini dibagi oleh ibumu?" to refer to a family house one island away from you, in that case you should use "itu". this sentence is perfectly normal if the object of the conversation "it" has been mentioned before, e.g if you are talking about a cake before and then you ask "apakah ini dibagi oleh ibumu?", is fine, but if you havent talked about the cake before you should say "kue ini" isntead. your example need a bit of correction, "apakah rumah dibagi oleh ibumu?" lacks some information, it makes people think 'which house?'. therefore we must add some information like "rumah ini"(this house), "rumah itu" (that house), "rumah pak X", (house of mr X). sorry if my explanation is a bit confusing