美國J1/J2離美時以Dual-status alien報稅 - 薪水

想請問大家關於Dual-status alien報稅問題

2019是我們在美國第3個日曆年,全家在2019/7/29離開美國回台工作.我們狀況如下:

太太J1在美國有收入有W-2,台灣醫院仍有給少許底薪
(台灣醫院送到美國醫院訓練,互不隸屬)
我是太太的J2,有辦EAD有收入(Uber,只有Tax summary,無1099-K/MISC),台灣無薪水.
有兩個小孩(1個是美籍,1個拿J2)
7/29後我們回台後都有工作.
台灣的銀行2019有存款有利息,也有股票股息.

請問我們若選Dual-status alien報稅,Pub519有寫到我們要填1040NR(寫上Dual-Status
Return),也要填1040當statement(寫上Dual-Status Statement).
幾個問題詢問:

1a.不能married file jointly,要夫妻要各別填一份.
1b.美籍小孩可以被父妻其中一人報dependent,另一人不用寫這個小孩,而J2小孩不能填
夫妻任一人的dependent欄位對嗎?
1c.拿J2的小孩是否要填8843 form?

2.1040NR和1040的薪水/銀行利息/股息 的填法有點困惑.美國的各種收入我們都會填入,
但是台灣的部份不太懂,而且又分成7/29前與後.我的困擾點在下2部份:
#Pub519 Chapter6的Income Subject to Tax這部份內容意思來看:
Income from sources outside the United States that is not effectively
connected with a trade or business in the United States is not taxable if
you receive it while you are a nonresident alien. The income is not taxable
even if you earned it while you were a resident alien or if you became a
resident alien or a U.S. citizen after receiving it and before the end of
the year.

2a:太太在台灣拿到的底薪,全部都是non taxable對嗎?
2b:太太和我7/29回台灣工作的薪水都是non taxable對嗎?
2c:non taxable一樣要加總進去填在1040與1040NR的Wages,Salaries,tips,etc那欄嗎?

#同章節,下2段How To Figure your Tax裡提到:
All income for your period of residence and all income that is effectively
connected with a trade or business in the United States for your period of
nonresidence, after allowable deductions, is added and taxed at the rates
that apply to U.S. citizens and residents. Income that is not connected
with a trade or business in the United States for your period of nonresidence
is subject to the flat 30% rate or lower treaty rate. You cannot take any
deductions against this income.

2c:跟美國貿易商務相關的會以RA的稅率來課.這部份是看Pub519 Chapter 4裡的
Effectively Connected Income,應該不包含在美國薪水和台灣薪水對嗎?

3.1040NR跟1040都要填,那算出來結果若不同,要以1040NR的結果來繳款或退稅嗎?

4.我們這種Dual-status alien報稅,因為12/31是NRA,所以不能用Turbotax申報.
那可用可報J簽證的Sprintax嗎? 還是只能用郵寄申報?

問題很多,感謝大家回答~Orz

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