1. Gray Market approach to working overseas. In some countries you can get a Tourist Visa for 90 days, others 30. Do not over stay your visa. In the Shenegan it is 90 days out of 180, and currently they are tracking it heavily.
Make sure you are in a place with great internet. Realize you will be raped on rent in a Tourist Apt. Since it is a Tourist apt, you may be forced to work from McDonalds, their internet in the EU and Asia is fantastic.
Australia is similar the EU.
Do note you may be able to rent a room from a local for a time.
Keep your mouth shut as to what you are doing, local authorities can be sticky
2. Check out residency options in each country. Panama is relatively easy. However you will be required to sign a years lease in most instances, and they do extradite from the US for skipping out on Apt leases.
3. There are enough folks from California on here who can give you a local flavor on the State. Do note CA is high cost and high tax.
4. Keep you taxes up to date. If you do the overseas option establish a residency in a low tax State, say AZ or Nevada. That way your only liability is the Feds tax bite.
Good Luck - note I split my time between Austria and the US as legal resident in both. I do not have to worry about the 90 & 90 restrictions. I do have to keep track of the number of days working in each country. The IRS and the Finanz Amt are always tracking me.