#2 is using the Standard Effect Rule from 6e1p133, it can be used or not depending on how you want the power to work.
#3 Linked vs Trigger - Linked to me involves the powers being combined into one thing. I use this power, this also happens as part of it. Trigger is whatever is determined can happen. If someone touches me, if I touch someone, if someone comes within 3ft of me, etc. It can be a bit blurry
#6 0 phase are little things that take no time. This power would be a 1/2 phase action (or all depending on when you take it). That's the beauty of the trigger part is it's automatically activating the aid at the same time. As mentioned earlier, without the trigger you'd have to do 1 phase for the Drain, then wait until your next phase for the Aid if Trigger wasn't added. Since it resets automatically you may use it on your next phase again. As for 'turned on' - you have instant, constant and persistent powers. Life Force Transfer is a one at a time attack. If you want to keep doing it you have to make the attack each phase. If it was constant (6e1p127 than as long as you pumped END into it it'd work, BUT you'd have to declare and make your attack role first.