Longhiver

"I'm always first kid" ability says : "it may make a 5 dice melee or range attack targeting one of the same enemy characters" Can Rex use this ability to shoot someone with a range attack even if he is already engaged with another ennemy character?

Cody innate ability (bring it down) allows for rerolls : "When an allied Clone trooper supporting character within 4 that has a one or more making a attack as part of a combat action, it may reroll up to two of its fail results." The rules say you can only use an ability once per turn but it also says innate ability are always on. So can the 2 characters from the support unit use the rerolls or only 1 ?