i never added drm to either so i’m not really sure why that is, maybe just a steam thing.
Hard to say, steam games that can launch without steam (e.g. Disillusion ST, the Hylics series if you know that one), can launch from in their folder without turning the app on (or if it's on, without showing as 'running', but this isn't a guarantee that it won't work without steam on). Just have to try it without the app on to see