I think complaining is necessary for getting past culture shock.  Complaining leads to  commiserating and that's what a lonely (and possibly scared) new expat feels the need to do.  It helps them feel not so alone.  They want to know that someone else felt the same way. (#7 and 8 on your list are key)  Even if you're around family and/or friends, there may always be a sense of alone-ness in a new culture.  This is true even of people who move to different cities in their own country!  And if the worst that us newbie-expats can complain about here is the cheese on our pizza or the homeless dogs, then I'd say that's really not so bad.