Here's the thing - I have now been a Surface Pro 4 owner for almost a year now - I have reloaded Windows (multiple versions) several times due to the fact that I am an IT Guru and a hacker from way back - I tend to screw up my Operating System quite often, so reloading it happens I'd say at a minimal of 2x a month. I have had some of the issues you are facing, but it was not my fault, nor the systems fault. The system is merely doing what you its designed to do upon a re-install or upgrade.
Here is the deal - Once you reload the system and get past all of the initialization screens, and get to the point you either activate your system - It can now update. The thing I was doing that conflicted with system peripherals, (sound, video etc) was allowing the Windows update to occur before I applied the downloaded Surface Drivers. This would in fact cause things not to work, and I would just have a slew of issues.
To avoid this in the future - you can try disconnecting from the internet, then installing your downloaded Surface Drivers - rebooting, reconnecting - and then the Window Update will sense that you have current drivers installed for your hardware, and commence to downloading other updates etc...
Currently I am running Windows 1607 *(Ver 14393.187) - I have ran all types of Windows Versions in order to "test out" which runs best with the Surface Pro 4 - and thus far - the above mentioned version seems to run flawlessly. One of the first things I did, within a week of purchasing my SP4 - was to reinstall Windows - as the version of Windows Pro that came with the machine seemed "clunky" and slow. If you need some assistance by chance on setting up a USB drive to install Windows - please let me know and I can send along a set of directions that will ensure first time success. Sometimes getting RUFUS to set up an Windows Installation using FAT32 can be a little tricky
I agree with what others have said in their comments - if you are so unsatisfied with your purchase - why haven't you just returned it? Being the IT Guy that I am - I have used all kinds, built all kinds of machines. I have to say that the Surface Pro 4, for its size - is one of the most Powerful Tablets I have ever encountered. I had a fellow IT guy log onto my Surface Pro 4 via TeamViewer and in less than 30 seconds of poking around - he asked me "dude - what kind of machine is this??" - When I told him it was a TABLET PC he was, as I am - astounded at its performance. This of course is based on which processor / memory you have. (SP4, i7, 16GbRam, 500GB HD) in which I gladly paid a whopping $2900 at the time. Now - whenever, if ever the SP5 comes out - I will wait for the "newness" to wear off, and the price to come down, and most importantly - the reviews by professionals to come out.
I have found that through several Forum Websites, most of the issues people are complaining about - are user issues. Which can be easily taken care of with a little Google, know-how, and ever so slight research/ Instead of complaining about an issue - Users should read and enjoy (if they like this sort of thing) - Enjoy the challenge of overcoming software issues. You see - your complaints are ALL software / driver related....This assumption is based of course that you didn't mention your Surface Pro 4 came out of the box without sound, and the other issues you meant. This occurred after either an update, or re-installation.
What I would recommend in your case - is going to the Surface Pro 4 Driver installation package, opening it, and removing all the drivers currently installed - reboot, re-install, reboot and I can guarantee that as long as your hardware has not failed at the core - your issues will be taken care of........This also applies to any other software you may have on your machine - after you re-install the SP4 drivers, remove the other software giving you heartache - and re-install it. I hope I haven't managed to offend you, or anyone else - but hey if the shoe fits.......wear it.....if it doesn't - Oh-well I tried.