I'm British, float between Portugal and Brazil. See my paying customers as being US, Canada, AUS, NZ and UK. Want the simplest structure, banking, accounts obligations and tax. Initially I don't need to draw revenue, my plan is to grow subscriptions, I expect to get attention, and down-road would entertain investment if that door opens. Initially my focus is simple old school approach of getting paying customers, and proving the business model works.
Hi read your question, I have some business endeavors abroad, between US & Dominican Republic, its my experience, that your first question should be: where can I cut costs, what country can I build a home base cost effectively since I know my business will be virtually remotely run anyway. Where would I suffer less tax/incur higher rental fees form my office/banking fees etc? If you can answer that one question then from there you'll deduce a destination. Keeping things simple is always the best advice I give to my clients. People become lost and overwhelmed when they dissect every little detail. Approach things from an "eagle eye" perspective and start zooming in but only AFTER you figured out the larger picture. Make a business plan that works for you and take the time to answer the general questions before you get lost in the tedious minutia of it all.
It's really impossible to answer this question without a fuller analysis of your specific tax situation. "Float between" won't be the terminology used in a tax treaty!
That being said, we've attempted to distill down different incorporation options at Incorporations.IO which is a free comparison tool for looking at global incorporation.
Also there are plenty of articles on our FlagTheory.com website which talk about tax residency, bank accounts, obligations in terms of reporting and more.
You should talk to an attorney.
Stripe Atlas could also be a good starting point.