Issues with running Ubuntu on a USB 3.0 pen drive

I wanted to experiment with creating a Linux removable drive and booting the PC to it. I created the boot drive and launched Linux from it. Few issues: Ubuntu will not read my internal hard drives, but will read my external hard drive. Attempting to install the NVIDIA drivers on it takes a god-awful long time, so I cancelled the driver install. Finally, when trying to put Ubuntu in sleep mode, it will not wake from sleep and I get a black screen. So I powered down the PC, removed the USB drive, and booted to Windows. Am I doing something wrong here? I want to run Linux off a portable drive and NOT my internal hard drives. Or maybe running Linux is not worth it? I may consider getting Windows 7 Professional for a sale price later on anyway and installing both Windows 7 and Windows 8.1 as a dual-boot configuration, but at a later time. Shortly after, I could keep Windows 7 and upgrade Windows 8.1 to Windows 10 for smooth software compatibility across the board.
 
Solution
The main issue is the default open source gpu driver does not work well with very new Nvidia hardware(gtx970 is very new). Thus sleep does not work. For legal reasons distributions cannot distribute the proprietary driver by default.

I would get a second USB or DVD to boot Ubuntu from then install Ubuntu to you USB drive like you would a normal HDD. Then you can successfully install nvidia driver.

I believe the distribution Manjaro does ship them out of the box and comes with a newer kernel. Maybe you should try this distro instead of Ubuntu.
https://manjaro.github.io/

As for not reading HDD? Linux should read them if they are properly formatted..
Post output of:
sudo parted -l
The main issue is the default open source gpu driver does not work well with very new Nvidia hardware(gtx970 is very new). Thus sleep does not work. For legal reasons distributions cannot distribute the proprietary driver by default.

I would get a second USB or DVD to boot Ubuntu from then install Ubuntu to you USB drive like you would a normal HDD. Then you can successfully install nvidia driver.

I believe the distribution Manjaro does ship them out of the box and comes with a newer kernel. Maybe you should try this distro instead of Ubuntu.
https://manjaro.github.io/

As for not reading HDD? Linux should read them if they are properly formatted..
Post output of:
sudo parted -l
 
Solution
OK, I can try the USB drive to USB drive install trick and see if that works. I can use an old USB 2.0 stick as the installer and install Linux to the USB 3.0 stick. My USB 3.0 stick has only 16 GB of drive space, so will that become an issue if installing Steam and some games on it? Can I still get Steam to install the Linux versions of games, such as Metro Last Light, to my HDD? Or will those games run poorly when using the USB stick as a Linux boot drive?
 
If you are expecting any kind of performance (comparable to HDD or SSD) from a USB flash drive you are in for a bad time. Read/Writes to flash based devices are SLOW and will wear out your flashdrive quick.

Installing to a HDD is a better option. Additionally 16GB is quite limiting if you are planning on installing games. I believe steam will let you choose where to physically install games to.
 
But I think I tried that once and Ubuntu hijacked the entire drive, taking my games and media files down with it. Then I uninstalled it and somehow, I lost some GRUB file or something and Windows would not boot until I did a repair from the media DVD. So is it safer to use a portable USB 3.0 hard drive, such as a WD Passport, to run Ubuntu on? Or is there a lighter distro that can run on a USB 3.0 flash stick that can run some Steam games? Sure, I would still use Windows often to play most games, especially games on Origin, but every once in a while, it would be nice to take a break from Windows and run the PC in a new environment. Some Steam games may even run better in Linux.
 
If you just install it to a small partition on your HDD (say 100GB) this will not happen. Sure if you choose option "erase and use entire drive" this will happen. Its very easy to do.. Just do option "something else". Shrink partition and install to the empty space. Of you want to purchase a separate drive to do this on that is OK.. Waste on $$ IMO.

The short answer to your other questions is yes, but they require more intamite knowledge of Linux. Steam only supported on Ubuntu.
 
I tried to install Puppy Linux to the USB 3.0 stick, but when attempting to boot from the USB 2.0 installer stick, it could not find the sfs file. If this does not work, then I guess I'll just have to ditch the Linux idea and perhaps get Windows 7 as an alternate OS later this year. Whenever Windows 8.1 is in need of maintenance or repair, then I could sure use a backup OS to fall back on.