I would personally try to convince your company the benefits of Flex Builder and using the Flex SDK over Flash. It is very much possible for the two to coexist. Animations and vector art can be designed in Flash Pro and loaded as SWF content into Flex. From gaming development and practices, it's a much better combination. Don't just say it, but get them into a meeting and present them with facts and show them you mean business.
I was thinking the same, if they call me it's because they need me, so, I guess, I can have an opinion in the tools we (I) use and how the development works. About the team, most of them are designers and few work with java and php backend; this make me believe the reason they hired me is because they wanted a As3 developer to work on more complicated games, hand on hand with the designers. It's hard work but right now I'm going to the meeting you suggested.
I don't see the problem if they don't want to buy Flex Builder I can use Flash Develop. I'll let you know how everything ends.
If they are stiff about it, I would jump ship. You will never build engine grade code from CS and as a developer you're only kidding yourself working with a designer tool. I know this isn't what you're hoping to hear, but it's a life decision right now. You can bite the bullet and read up on the Flash API (Adobe Live Docs) and CS help manual, but that's no life of a developer.
I guess they can sink alone Thanks for the advice. Take care.
Forgive my crappy english