why don't med just heal EVERYONE on it?
why it takes 35 seconds to take another booster?
because its a bug where you can't retake your poison until the poison is gone
Let me delete that double post for you. Here it's done.
Well, that booster thing might be considered a bug, bug if you look at the source code ( specificaly tremulous.h ), you'll find those cute little lines of code :
#define BOOSTER_INTERVAL 30000 //time in msec between uses (per player)
#define BOOSTER_REGEN_MOD 2.0f
#define BOOST_TIME 30000
And thus it is not a bug, it is a feature

Edit, and now, for an easy to implement medipack suggestion which will solve the current problem, and give a very small boost for humans : medistation queue is only for health point regen. On the other hand, even if the medistation is healing someone, you can still use it to get cured of poison or to get a new medikit. It will continue healing the player that was using it at the same time.