For anyone curious, I've found CS5.5 works well, as long as you're offline when you put in your serial and offline when you open it. (and after you close it and before you reconnect to the internet, terminate all processes with cs5.5 in the name using Task Manager.) So you can definitely use Cs5.5 without any sketchy hacks you don't know if you can trust.
its a bit of a pain to be offline as you develop, but its not so bad.
if you ever are accidentally online as you use it, nothing will happen the first time, but after 2-3 times it will downgrade you to the trial version after it tries to find the long-offline activation servers. yes, even if you have the disk and serial legit next to you. so stay offline. Don't sign in with or make an adobe account. don't send feedback or usage data, etc.
I reccomend using wine as it runs okay on linux with some quirks. but if you ever fuck up and go online wine also has the benfit of having an easy nuke-it-all-and-restart option. just delete .wine and start over. (newer versions of creative suite explode shrapnel into your registry making it hard to nuke on windows. adobe was sneaky. once you're trialed, its hard to get untrialed)
you may also try a VM or some sort of solution that blocks the Flash CS5.5 from any form of internet. ymmv.
I hope this helps anyone with legit copies of CS5.5.
or ya can use flash 8 (its actually better thsn you think! just keep in mind that flash 8's AS2 is somewhat different than the revised cs5, cs6 etc's versions of AS2, some tutorials for AS2 might be broken on newer versions of non-animate editions of flash. ie some text related things may cause trouble)
if you know actionscripting, JPEXS's FFDEC also can create blank .SWF files that you can hack your stuff into. even has a 'basic mode' editor that is visually similar to the adobe editors. still an early on solution, but give it a shot
Thank you all so much for These flash jams. one of the only joys left in the world for me. don't be too harsh on yourself if you're new to flash. I banged my head against the wall for 2 years before I could ever make any simple game back then, so rest assured you're likely not stupid.