So are the starter and gravity feed figs for GOTG legal in modern now that theyre out, or is there a time that they become legal for use. I have my first modern event this weekend and one of my local stores just got their stuff today and I was there as they put it out.
Just wanted to make sure if I wanted to run Rocket i would be able to and wouldn't have to change any of my team ideas.

There shouldn't be anything Preventing it from immediately being active. However best option is to ask your judge. That person may say no until everyone has a chance to get pieces and open them up and play ect...

They need to be out for 7 days for use in modern. They will be legal on the 9th.

That's specifically for a WizKids-sponsored tournament. From the current Comprehensive Tournament Rules (underline added):

Figures are legal, per the tournament rules, as soon as they are released. As posted above, WizKids requires figures be available for at least 1 week before they are used in WizKids sponsored tournaments (conventions). Its best to check with your judge. I've had some local judges also adopt the 1 week rule.