Can an individual who lives in ID avoid the Idaho income tax by working physically in WA and no work in ID at all? If a WA individual works remotely for a client located in Idaho, is that considered WA source of income or Idaho? If the Idaho employee works for both States, does it mean he has to prorate his comp among 2 States for SUTA and other misc local taxes like the WA paid leave and medical leave premium?
Normally, you may be able to avoid tax in Idaho if you work in another state, but since the state is Washington which has no personal income tax, it will not work for you. You would get credit for taxes paid to another state on your Idaho return, but since you paid no tax to Washington, you will have to pay your full Idaho tax.
A person who works in Idaho has Idaho source income and has to pay Idaho tax on it.
Unfortunately, TurboTax is not licensed to give advice on payroll tax laws, so I can't answer the SUTA question.