Does this work for international travelers with multiple sim cards? (in US, India and other countries ?)
You need this phone
when you are home alone.
Spend your money here
don’t buy all that beer.
Really helpful in a cyclone.
Is Scratch and Dent phones New or Used?
Used. They are refurbished, but the scratch & dent means they weren’t refurbed to factory condition. They will have imperfections, small scratches, dings, etc.
Careful - the last time I bought an unlocked S6 from Woot advertised as the AT&T version, Woot sent me the Sprint version instead (model SM-G920P). Make sure to check you model number when you receive it.
Your “Will Your Phone Work” tool gives results regarding the submodels of the Galaxy S5. But your pages and specs for the S5 do not tell the submodel. Ooops! Can’t tell if it will work abroad without the submodel…
Submodel is SM-G900T.
I use mine in Belgium, but pay attention to the bands. Every country is different.
Buyer beware. If you get your phone and knox has been tripped, you probably have a lost or stolen phone. I bought an S5 from woot last fall and this last month service suddenly stopped because the phone was reported stolen. Woot did return the purchase, but had to go through the hassle of finding another phone without having a working one. 
Are the batteries new or used?
They will be tested and replaced if necessary.