If I'm following you right, keeping everything in sync is pretty easy. Assuming you have a desktop and a laptop, you can share out the steam folder on the network and copy back and forth as you need to. I have a robocopy script set up to automatically sync my steam directory to an external hard drive. If the game doesn't register in steam on your laptop after you copy it, just go to download/install the game, and it'll scan the existing files. Only takes a second. Ditto for syncing up to my laptops.
Heck, you can probably map the share as a network drive and play right off that if you really wanted, so long as the game or steam doesn't check to see if it's a remote share.
For saved games outside of steam cloud, I use Dropbox. I stash all my saved games folders on dropbox, and then create a junction point (mklink command in a command window) to link where the game expects the saves to be with my local cache of Dropbox. That way all my saved games are always backed up online and synced between all my systems, even my girlfriend's desktop. And, because I synced all my games onto her desktop, it saved her from a multi-gig download over a 512 kbit connection when she purchased a game under her account.
The only caveat is that you can obviously only log into steam twice with the same account and be online, and games vary where they stash their saves. I use a different batch file for each game to make things easy.
Of course, if I misunderstood you, I could be WAAAY off base 😛