1. LD在美國工作20多年， 交了20多年的SS， 那麽是不是以後我們沒有任何希望再領SS retirement 了， 我不工作， 因為LD沒法領， 那麽我的spouse benefits 也沒有了， 對嗎？
You and your husband can collect SS. His benefit doesn't expire.
2. 我準備今年疫情鬆了以後， 也帶孩子回國 join LD， 那麽今後我們報稅的perminant address 就應該寫中國地址 對嗎？ （現在美國的房子準備出租）
Yes.
3. LD 沒有了綠卡， 工資是從國內單位領的， 那麽他在中國的收入就可以不報稅了， 對嗎？LD美國以前存的401 已經轉成IRA了， 我準備每年把一些ira convert 成 roth ira， 那麽這部分收入還是LD的， 這些收入還要報稅， 對嗎？
This is kind of complicated, you have several choices, see https://www.americansabroad.org/nonamerican-spouse-us-tax-implications/#:~:text=Even%20if%20you%20both%20live,she%20was%20a%20US%20citizen.&text=Also%2C%20if%20you%20each%20qualify,per%20year%20of%20foreign%20income.
4. LD是中國公民， physically 住在中國， 我是美國公民， physically 也住在中國， 我兩還可以繼續 tax file jointly 嗎？ 收入就是LD的 IRA convert Roth 的部分 和我名下的房子出租收入。我們在美國沒有primary ａｄｄｒｅｓｓ， 隻有出租房，那麽我還需要報州稅嗎？
First, your rental income still subjected to state tax because the house is in the state.
Second, you might still be a resident of that state because you kept your home in the state, which means you have intention to return to that home in the future. So there is a possibility that you still need to pay state income tax on all your incomes. Check the state tax law for certain.
５. 如果１０多年後， LD退休了， 想回美國， 我們的孩子能給LD申請綠卡嗎？
Yes. Either you or your child can sponsor your LD's greencard. But you or your child has to have income to financially sponsor him.
