A - abstract attack (unit moves to selected point, attacking all enemies it meets on the way);
S - stop the unit (cancel all moving orders);
D - lock formation (units hold their positions on/off);
~ - battle results screen (shows teams/armies statistics);
Space bar - team colors (switches the mode of representing units -shows units by player colors or by team colors as enemies and allies);
Enter - send chat message;
Ctrl+Enter - message in command chat;
Ctrl+A - select all your units;
Ctrl+1...0 - assign a hotkey to unit or group;
1...0 - select a unit or group with hotkey;
Ctrl+LMB on unit - add or remove a unit from the selected group;
Ctrl+rectangle draw - add units in rectangle to the selected unit;
Ctrl+RMB...+RMB on the battlefield - add several checkpoints for units to move to;
Tab - scrolling between units inside a selected group;
Esc - fast exit from the battle;

Debug hotkeys:
F1 - create a Dump Log + Screenshot - use in case of "logic errors";
F3 - hide/restore interface (for screenshots);
F6 - extended log - use in case of "invisible unit" errors;
F9 - switching between camera move modes