- I made sure somebody would take care of my incoming mail at home. Also make sure your financial situation,tax etc is handled.
- learning the local language + spending time on your own stuff sounds awesome
- 3 months for $5000 should be definitely doable. Renting an apartment beats moving around from hotel to hotel, however you might be interested in checking the country too :-) Mostly, avoid restaurants that serve western food and touristy neighborhoods, as your money will not go far there.
- doing web dev work would help you keep up to date. You can also see whether locals need help with their website/design needs (for example hotels, travel agencies etc.)
Relax. I know it sounds daunting when you're at home, but it's really not as dangerous or complex as people say. Don't forget to pack light. I have a 35-liter backpack and that's been enough for 5 months traveling/living in SE Asia, including laptop for work :-)