For how easier to start up games, I've had these two thoughts, short-term and longer/medium term:
(1) drop-down values
IMO likely a quick win here, have the 'to', 'cc' and 'game-id' fields contain drop-down values of previously used values. This would be somewhat similar to how the 'forum' field is a drop-down, but would allow new entries to be added. Useful when switching between multiple opponents when playing multiple games. Picture below has red circle where to add drop-downs, green check to call out the existing drop-down:
(2) Save Game Manager / UI
To load save games today, we show a file menu chooser and rely on the user to find the save game file and load it.
The suggestion here is to build a UI that would show a list of save-games that a user can use to select/load a game. IMO the nice thing here is we can help organize the various save-games and make them easier to launch. For example we could have a 'tab' or a filter to show the auto-saves. Before launching any game the listings would show the map-name, the game type (local/PBF/PBEM/live), game-round.
There's a few things to solve here, mostly how to persist and read data about save games. A brute-force implementation would scan from a list of folders and load each save-game and gather the round/map info that way. Less obvious is how to code/solve for a player listing and to encode & detect if a save game is local/PBF.
An important eventual element of this is that we'll be able to abstract away the physical file and the games to load could include for example PBF and load a file that was posted to forum.