You definitely need to talk to an accountant. I will try to answer in a general fashion so that you get the overall picture.
You can claim deductions if your spouse makes less than a certain amount. Deductions for kids are available as well. But no such thing as a lower tax rate.
EP holder or not, you are taxed the same as Singaporeans. The relevant question is whether you are a resident. (working or living in Singapore more that 1/2 year--with some exceptions) Non residents are taxed differently. What I am telling you refers only to residents.
Housing is taxable, most likely not at the full amount, but at 10% of your employment income. (Complicated rules exist regarding whether you are director or your place is rent-controlled, oh, also if your place is furnished, they have a table to refer to for that.)
Home leave costs are also taxable, but whether you went once or more makes a difference as to how much of the actual cost is considered your income.
Maids--wages are NOT deductible. If you are a working woman twice the levy can be deducted, but if you are a man, no luck.
Please talk to an accountant. Or at least check out the IRAS site.