I'm having similar problems as well, plus a few others. I posted early this morning and while it didn't show up on the "new" window, it did show up on my blog. I got a reply from one of my followers and so I know it went out, but when she tried to resteem it, the little icon turned blue but the resteem didn't show up in her blog or mine.
Also, I checked my "feed" early this morning, read all the interesting posts, came back an hour later and there were several posts from people I'm following that were up to 6 hours old. I know they weren't there before since I'm not following that many people and these were bloggers I always read. If this is just a software glitch, it's a pretty selective and sophisticated one.
That first paragraph of issues you described are unlike anything I've seen so far. Very odd.
"came back an hour later and there were several posts from people I'm following that were up to 6 hours old."
That's also very odd. Perhaps they were entered to the blockchain 6 hours ago, but Steemit was unable to access them until you came back later because of Steemit-related issues.