回--和7岁的儿子买自住房可以申请8000元的税务回扣吗

no.

beacause房产买卖是个形成contract的过程。

Contract的首要条件就是--Legally competent parties。

Parties entering into a contract must have legal capacity to do so.

Almost anyone is capable, with a few exceptions：

A person must be at least 18 years of age, unless married, in the military or emancipated.

A minor is not capable of appointing an agent, or entering into an agency
agreement with a broker to buy or sell a real estate!

but Both minors and incompetents may acquire title to real property
by gift or inheritance.