1.because your brother is student
and do not meet any one of “must file 8833 “rule and he meet one of exception
to “must file 8833” . so your brother do NOT need to file 8833. For my personal
experience, for safe consideration, always file it to avoid the $1000 penalty.

2. you and other person answered
question  here mixed 3 different
concepts

standard deduction($5000 for year
of 2006,), personal exemption($3,200) and tax treaty  exemption(up to $5000 for compensation to personal service for F
J,M,Q visa holder).

As a F1(even you are in OPT, you
still F1 ) he can not claim the $ 5000
standard deduction ,only eligible for 
3200 personal exemption and 5000 tax exemption..

3. 5 years later if this Chinese
person  are still a F1 holder, he can
still benefit from the tax treaty provision even you are beyond the normal
5-year period  and  he can change the tax form to 1040 instead
of 1040NR to enjoy the standard deduction.