2 Dayz Accounts

[deadly serious]

Would I be able to use the same Arma 2 keys for both of my steam accounts? And would I have 2 different characters on Dayz?

 

[iFrostys]

No, each Steam account must have a different CD-Key (aka different copy of the game) because your CD-Key is, in essence, 'migrated' to your Steam account.
Hope I helped.