Among the most significant changes with this year’s Elements releases has little to do with new features but instead concerns the ways users purchase and own the software. While prior versions of Photoshop and Premiere Elements have been lifetime licenses — the user buys the software and then owns it indefinitely — this year’s release has moved to a three-year license term.
Note that a lot of games on steam don't have any DRM, either. It's probable that if you have large library, a lot of your installed games will run without steam, if you go and start them from their exe.
So you can likely archive at least some of your steam games by simply keeping them installed, or even squirreling away the install folder somewhere.
All Steam games have SteamDRM and you cannot run them without Steam or without the license, otherwise you could just buy a game, backup the installed files, refund the game and still have complete access to it.
On the other hand, it's quite easy to bypass that DRM with a crack.
No they don't. The dev has to opt to use Valve CEG (custome executabke generation) for that to be included in the game files, and that is entirely optional.
On these games, you can do exactly what you suggest.