ii) definitely not true, but it doesn't hurt. Many corporations have policies requiring internal job postings for certain lengths of time before being able to hire someone from outside. The idea here is to promote internal, upward, growth with the hope that most people will be hired at the bottom and "work their way up". Smaller companies / startups tend to not have these policies and / or are not large enough for that to work so already having a job there doesn't necessarily benefit you.

iii) this has 0 impact in my experience. I do not know, or care, where you're from or your personal background and nobody should ask you this and you should not reveal it. What matters is; are you qualified? Do you have the experience and can you show me you work well with others and know what you're doing. At an entry position it's more about personality than skill. Although skill is still very important.