GREEN LANTERN CORPS - When using the Carry ability, characters using the Green Lantern Corps team ability may carry up to 8 friendly characters.

So all characters have the carry ability right? Does this mean , could carry other , ? Or would a , character with GL TA only be able to carry 8 ?

It says "WHEN using the Carry ability." There character must be able to Carry in the first place. This doesn't grant the Carry ability to characters that can't normally use it, nor does it alter the way Carry usually works except the "up to 8" part (so the combat symbols of your characters still matter).

So if a standard sized character had this TA, it would only be able to carry characters.

The GL TA does not confer the Carry Ability. It makes an allowance for characters who have it and use it.

Also, it does not allow a non-flier to carry 8 tiny-sized. That is because of:

Good catch. I never noticed that. I wonder if it is new(ish).