when I download games they still aren’t ready to play upon first startup, they need additional downloads/connectivity upon first launch
This specifically bite me in the past. Despite me knowing this being an issue, I completely forgot when preparing for a longer offline session. Some games need to run once to play them in offline mode, but I believe this is not required for all games. It's not an issue with the Steam Deck specifically, but with Steam in general.
Maybe instead running the game automatically, there should be an indicator ("green dot color" and not ready as "gray dot color") that the game didn't run and is not ready for offline play (at least from side of Steam). And even further, the indicator could stay at "No Offline Play" ("red dot color") showing the game cannot be played offline. This would be a setting by the publisher to show its not possible.