Super slow reply.... so sorry. These answers may be too late to help you, but maybe they'll help someone else. OK, let's get to answering your questions.
The simple answer is that you need a home base in order to collect tax-free monies as a traveler, which is really where the money is. Although, with having been a PT for a long time, you might not find the difference in your current pay versus traveling to actually be all that much. The true definition of a tax home is dependent on you being financially attached to a place (i.e. Owning, mortgage, or "fair value" rent). People do pay their parents rent, recruiters may tell you that any number of things is fine..... but to truly cover your butt, you should be paying a normal rent somewhere and have at least a bedroom that is reserved for you should you be audited.
Ah, pay. Here's a piece from a ways back about pay: http://hobohealth.com/wordpress/contrac ... -you-paid/
The short answer is that as an experienced PT, I would make sure you are making at least $1600/wk after taxes including your housing stipend (less if you decide to have housing provided for you). There are, of course, some exceptions - places like Hawaii might pay lower than that - but if an agency is giving you offers in the $1400's, walk away.
I'll shoot you an email with the recruiters I typically use. Hope this was helpful.