I understand your sentiment completely. My intention is to be as invisible as possible and make little to no social impact, which is how I behave here as well. In IRL, I'm nice to everyone I meet and I don't think I ever participate in any discussion that would include me providing my opinion on a topic, regardless of whether or not I feel informed about it. I leave that for everyone else, lend an ear if it looks like they need to say something and then just non-commitally nod that I understood them. It's a rare occurrence as I don't interact with many people outside of stores or wife and child. If my life continues it's current trajectory, the locals will hopefully not even be aware of my existence.
I'm not sure what an economic migrant is. Does that mean moving to a country because they want a bigger impact of their money to live a fancy lifestyle or does it mean moving because they need a cheaper economy to live? As for distorting the market, I don't think that's a risk as we will be working out of necessity and don't have a bunch in the way of savings. We're not what the US would call wealthy or even well-off. I guess we fit square in the center of middle-class but that will drop when moving.
Thank you very much for your thoughts.