1: Yes, as soon as you apply it (the code to activate the booster), ALL your characters (both new and existing) gain access.
2: No. Basically the booster applies to all characters regardless of origin or concept-appropriateness. So you can have science characters dropping the Mystic Fortune from the Magic booster. You can have your witch character using the Super Serum costume change emote from the Science booster, etc.
3: Welcome back. And don't worry. You're just being slapped upside the head with a lot of new data all at once. You'll assimilate quickly (you DO have the Cyborg pack RIGHT?)
Clicking on the linked image above will take you off the City of Heroes site. However, the guides will be linked back here.
All your characters, including existing, should have access to the booster packs.
Origin does not matter.
You should be able to find your booster pack powers, if you look in your power window under 'inherent'. From there you can draw it to a tray.
OK. Thank you, great info. But perhaps I should have been more specific when I asked how to access the powers.
Where will I find the Mystic Fortune & Self Destruct powers? In my power tray? Or do I have to do something in game to get them?
And yes, I do have the cyBORG pack and I am assimilating well.
Thanks again. Looks like I am a little slow on my replies.
Thanks again all.
Snippet:
[ QUOTE ]
...assimilate quickly (you DO have the Cyborg pack RIGHT?)
[/ QUOTE ]
I see what ya did there. 
*Extends Borg nanite probes*
You will be assimilated, resistance is futile. Your biological distinctiveness will be added to our own.
http://paragonwiki.com/wiki/Issues
http://paragonwiki.com/wiki/Booster
Zloth's Update History
Speeding Through New DA Repeatables || Spreadsheet o' Enhancements || Zombie Skins: better skins for these forums || Guide to Guides
If you bought the boosters, and have applied them in your account manager at Plaync.com, then you should be able to log into the game and:
1: On the Power trays, click "Powers".
2: Your Temp/Accolade, etc powers will be down the right-hand side of the window that pops up.
3: Simply click and drag the power down into your Power trays.
Quick pictoral howto
Clicking on the linked image above will take you off the City of Heroes site. However, the guides will be linked back here.
Thanks again to each of you. I appreciate your responses and advice. I am enjoying the game very much :-) and enjoying all the changes and upgrades... except AE, just haven't gotten around to checking it out... but from what I have been reading I might be better off just sticking to the game as is.
Again, thank you all.
Good Hunting!!
I recently read about and then purchased all three Booster Packs, but now I have some questions.
1) Can existing characters access the perks of these Booster Packs? If so, how? (specifically I am curious about the powers)
2)Does the Origin of the character have anything to do with the availability of the perks of the Booster Pack? Example; Must be Magic Origin to access Magic Booster.
I have been away from CoH for a long time and am a bit overwhelmed with (and a little ignorant of) all the changes (but mostly in a good way).
Thanks in advance for any and all help.