第二个问题俺来回答：

interest是要交税的。

如果你们file jointly,实际上你就放弃了你的non-resident的tax status,所以interest是要交税的。

理解不对的大虾们指正

问题1 - 正确的做法F1 $5K 选择joint file是不应该再减掉的。因为$10K的DEDUCTION已经包括了。F1应自动放弃$5K如果选择joint file.

具体怎么处理，LZMM自己决定吧。

The China/US tax treaty has a savings clause. If you are eligible for the tax treaty exclusion on the 1040NR, you also get it on the 1040. Add your income on line 7 of the 1040, then subtract out the excluded income on lin 21. On the secondpage of the 1040, you also get the married deduction of $10,000.

Q1: Did you mean 8843 instead of 8848?

You can claim 5K tax treaty coz even you are resident for tax purposes, you still qualify. See Article 20,plz.

Q2: You have to pay tax for interests coz you are resident instead of NR now

But I guess this is the trade off, you gain alot from Std. Deduction. NR do not have S.D?(plz correct me) And MFJ has lower tax rate than MFS in which NRs have to fill that way.

以下是引用avo在2006-4-2 16:09:00的发言：

Q1: Did you mean 8843 instead of 8848?

You can claim 5K tax treaty coz even you are resident for tax purposes, you still qualify. See Article 20,plz.

Q2: You have to pay tax for interests coz you are resident instead of NR now

But I guess this is the trade off, you gain alot from Std. Deduction. NR do not have S.D?(plz correct me) And MFJ has lower tax rate than MFS in which NRs have to fill that way.

谢谢，这下我可省了好几百啊，有更多银子孝敬父母了

以下是引用avo在2006-4-2 16:09:00的发言：

Q1: Did you mean 8843 instead of 8848?

You can claim 5K tax treaty coz even you are resident for tax purposes, you still qualify. See Article 20,plz.

Q2: You have to pay tax for interests coz you are resident instead of NR now

But I guess this is the trade off, you gain alot from Std. Deduction. NR do not have S.D?(plz correct me) And MFJ has lower tax rate than MFS in which NRs have to fill that way.

That is correct. Only residents of India can claim standard deduction.