Again something to highlight and I have read rules regarding but it doesn't state much.

When a Rebel player collects a crate they hold the crate in their possession and take the loot card which remains with them during the mission and discarded / returned to deck at end of the mission.

1) If a Rebel is carrying a Crate and is wounded during the mission, does he/she release the crate from their possession effectively loosing 50 credits.

2) When a Rebel player chooses to use the loot card be it healing or a stim does this count as one of their actions for their activation or is this in addition to the two actions per activation.

1) No, discussed in a thread just yesterday.

2) Does the card have the action icon in front of its text?

1. Played that right then

2. No action logo on the card it just tells the Rebel what to do and then discard

Then it doesn't require an action to do it.