(2) Do be sure to proofread your written business communications; non-standard abbreviations like "xp", "cert", or "pc" (not capitalized), and a run-on / fragmented sentence style will be instant deal-breakers to many, many people on the hiring side.
Your Stack Overflow CV, in particular, definitely will not work with 98% of regular business employers out there, simply on the basis of the writing style and over-personalization (i.e. the way you make it all about you and your story... rather than the skills you can bring to the table).
(3) Whatever you do, never mention that you're homeless of course. This might get you sympathy from some people on an abstract level -- but a much stronger impulse will force them to compartmentalize, detach their feelings from the situation, and focus on the job they have to do (namely, finding the right person for the role).