Maybe I want games installed on different hard drives. If the games all use Steam, I can't do that. Do you see the problem yet?
You can do it. NTFS and many other file systems have some neat features. For Windows they are just hidden in command line operations by default. Thankfully there are handy things like this:
http://schinagl.priv.at/nt/hardlinkshellext/hardlinkshellext.html
All you do is install the game and then after it is done close Steam out entirely. Right click the directory name under for example:
D:\Program Files (x86)\Steam\steamapps\common\gamename (you're right click "gamename" in the tree) and click cut. Then you'd paste it where you want it on the SSD. Then you right click the directory on the SSD and choose "Pick Link Source." After doing that in a blank spot inside the common directory or on the common directory in the tree list click "Drop as..." and then "Junction."
What this will do is effectively allow Steam to use that directory on the HDD but it will point to the actual directory on the SSD. Steam will not know the difference. You can do this with any other directory you want too, such as the data directory for Oblivion, etc.
Hard Links allow a single file to exist in multiple places in the same file system, without taking up multiple places on the disk. That is a feature that would not really help with your desire here though since hard links only work within the same partition. A symbolic link can link a file on one drive to a location on another drive, but for your purposes a junction is the best solution.
You can also change the default location of the various Windows directory settings:
http://www.vista4beginners.com/Move-user-files-folders-to-another-partition
http://benosullivan.co.uk/windows/how-to-move-the-program-files-and-user-folders-in-windows-7-to-a-different-drive/
There are advanced ways to configure those directories by configuring a custom (perfectly legal I must add) Windows installation ISO for use on a DVD or other bootable device/network drive as well.
The junction thing alone would solve your install location issue with Steam though.
Try running a game. It ramps up to around 70-90MB usage and about 2-3% CPU usage.
Basically a digital game store application that alos provides chat services, achevement tracking, DRM, and in game web browsing of the steme store. Basically everything I personally don't want with Skyrim.
You can turn off the in game Steam UI integration. That said, it does use about 30MB for me. I still far prefer it to other DRM options though.