This accolade is earned when you defeat a Watcher Knight with a grenade. You can cook your grenades (hold the grenade button); when the explosive is sparkling yellow/gold constantly, it will explode approximately three seconds after being thrown. Naturally, you will want to damage the Watcher Knight (looks like a D&D naga) so its emitting lots of blue smoke before you try to down it with a single grenade.
This accolade asks you to free fall for ten real-time seconds. The easiest area to do this is the same area where Will first learns to fly (Episode I, last area). If you need the extra distance, you can use the hole to the prison that serves as the level's exit for a few more seconds of free fall.
This accolade is earned by collecting tech points. This refers to the lifetime total in your profile or gamertag, and not the current total of points (so, feel free to upgrade your weapons).
This accolade is earned by disabling the Watcher Archon (four legged mech) and then using the melee finisher on its tail (not its head). Follow the button prompts to complete this task.