Removable Storage

If I rename them then I'm still stuck with them there, right..

It isn't an issue to have them visible in Explorer. If you rename them...there's no confusion. My card reader uses M, N, O, and P. I have several other drive letters in use, plus several network drives connected, and there's no confusion.

Can I use any name or letter that I want ?

You can use any free letter you want. For example, C, couldn't be used, obviously. My three hard drives are C, D, and E. My optical drive is F. Then I have a huge gap separating the rest. As I said, M, N, O, and P, are my card reader, and S, U, and Z are network drives. Drives that allow it, like hard drives, get names, like my C drive is SYSTEM, D is STORAGE, and E is MEDIA. The network drives are recognizable by path. There's very little to memorize, and it sounds like you are over-thinking or over-complicating your setup.

Here is a screen shot. hope I did it right

That's definitely a card-reader. If you go into Disk Management, you'll be able to right click on any drive and change it's letter (except C).

To help avoid confusion and keep the Explorer window uncluttered while viewing the "Computer" folder, while in Explorer, do:

Alt-T -> Folder options -> in View tab, select "Hide empty drives in the Computer folder", click OK.

That way they won't appear unless you insert a card into the reader. After you eject the card the icon/listing for it will disappear.

When I click Alt-T I don't have a folder option.

I found it and its already checked.