Hi, can i combine the 3 cards at the end of an activation???

Force Rush is "at the start of your activation", so it cannot be played at the end of an activation. The 2mp gained goes into your mp pool.
Dark Energy is "during your activation", which means it can no longer be played if you have decided to end the activation. It can only be played during your activation when you are not resolving another ability. (But you don't need to end movement to play that.)

So no. The order is always Force Rush, Dark Energy, Force Surge.