All good points! One thing I'd like to add is that new users shouldn't forget to post in a community - I mean one of the few communities that are active, e.g. GEMS, LeoFinance, OCD, OnChainArt or StemSocial, depending on your interests, or a language-specific group. And d.buzz is technically a community too. It's a good way to find people with similar interests, and members will be more willing to read a post from someone they don't know there.
I'm not so sure about the generic communities as some are just too big to really get you noticed. GEMS seems be anything goes, but others may be better. A more specific community may be better even if it's small. I do agree that finding those who share your interests is important.