Living in NL while working US Remote Job

Welcome on board 

I can't help you much but I do know one thing for sure: no matter where you are in the world, if you work you need to pay taxes in the USA.

There are so much threads on this topic floating around on the site that it will be best for you to use the search bar to find them.
Or go to the USA forum for better replies.

You will need a residence permit to live and work as self-employed in Holland; this link will take you to the relevant section of the IND website that explains this.  At the top of this page is a series of links, select the handy tools option and it will take you to a series of articles relevant to moving to and living in Holland.

Where you pay taxes is decided by your country of residence.  Also, US citizens living abroad still have to submit a tax return to the IRS and depending how much you earn, also a State Tax return and you can still be liable for US taxes.  I'd advise you to speak to a US tax expert for the current data and the consequential US tax implications.

Also, while there is a double-taxation agreement between the US and NL (which means you won't be taxed twice on income), that the Dutch tax system has additional social taxes which are not included in the agreement and you'll have to pay in Holland.

You also need to consider the compulsory medical insurance.

Hope this helps.