preferable you declare. at least IRB know you're so called "honest" to declare. Whether you declare your blog income or not, it's very subjective. I would recommend you to declare. at least when you mentioned about buying hse, it's easier.

ur education, i don't think you can deduct in that way cos that's your mom, not Registered Financial Institution under Bank Negara.

buy car is easier and not involve much of income tax. but buy hse / property is different. you need to supply your IRB's relevant document when apply loan.

just my 2 cents.