Number 1: I think this is due to specializing in Ruby on Rails which is falling out of favor? Or your city location? I know in my location the average job hunt is 2 weeks.
Number 2: As someone that interviews people alot, this is cuz MANY people who apply CANNOT code, no matter what their resume says. We have had people leave and never come back during our console app on site test (read in a text file and print out its contents with some minor formatting). This is resumes with 10 years plus experience in the language supposedly. And the computer has whatever IDE they prefer and full internet access!
Number 3: I agree that CS type questions are pointless unless you are doing stuff like that on the job. We have stopped using those.
Number 4: We now require an onsite 2 hour code project (designed to fit in that time frame)
Number 5: True
Number 6: We use headhunters to weed people out but that is about it. For one position the head hunter roughly run 15 people applying for each 1 possible person to pass to us for the next step. Again, most fail a mind boggling simple phone interview process for people who claim 10 plus years experience in coding. Not knowing what the static keyword means in C# when they say they are skilled in C# for instance.
Number 7: Don't have an opinion on this
Number 8: Again this seems to be your physical location. At ours there is roughly 3 open positions for each matching person.
Number 9: Our company does not discriminate on age and are desperate for qualified people with experience. Many times a candidate regardless of age is stuck in one tech (winforms, MVC, Ruby on Rails (:P)) and we more discrimate on someone who is not showing growth in their tech skillset. For example, are you learning the basics of a cloud stack such as AWS/Google/Azure?
At the end of the interview, I would recommend asking "are there any concerns or issues you would have with hiring me for this position?" and LISTEN to their feedback. I am sure there are some bad companies but for the most part it feels like you are not interviewing well for whatever reason. Maybe you are coming off as defensive or hostile when questioned? I would also reach back to the company and ask why they did not choose you. Most companies are way to busy to tell each person why they were passed over, but if you show an interest they will usually respond.
Anyway good post and good luck to you!