I don't understand all that screening bullshit -- what do you proud of, why so, why such? Somebody, tell them (HR people), it doesn't matter for a person who codes, does an architecture, ops your stuff, etc...
1 & 2) Yes. This depends on the type of visa but for an H-1B, where a degree is required, you could get your experience evaluated as the equivalent of a bachelor's degree and that would be sufficient.
3.) That's not correct. It depends in part on the green card category but we get green cards for people without any tertiary education all the time.
Why?! Why at this topic I get so much ads? Is it a part of their IPO? Or what? What the hell? It's a "little bit" annoying. You wanna share your experience -- go ahead, we're ready to listen.
Yeah, we have a plenty alternative services, but only two dominated mobile OS (and three desktop). Isn't you are looking for a problem in a wrong direction?
From my point of ignorance, the best thing is just start working. Seriously! Get a task and start solving it by your own. Even a simple task in a big project gives you a bigger picture that tons of useless meetings.
I suppose, it's worth nothing to read an article, which compares benchmarks of Ubuntu and CentOS. It's too bullshit. Be honest, compare comparable things.