can u still fire and hire coaches with owner mode turned off

what is the best playbook

SARS
SARS
SARS
SARS

I think you should able to hire coach or fire coach even you turn off the owner mode. All you have to do is keep checking the NFL news to see any coach whom you want, been fired recently by the computer, and then go to coach option and select him.
It depends on who you are talking to or your styles of your offense. If you like to pass a lot, I would recommend Raiders play book, and if you want to balance your offense which I highly recommend you, I use the Packers, or west coast offense. If you want to run, I think EA also has a play book which are heavily desired for running plays.

You can fire/hire coaches without owners mode, all you have to do is change your coach under coach options.

And I find the Viking's playbook as quite a good fit for most teams with a decent wide reciever, however, teams with sub par recievers (Such as the Chiefs) will fall flat with the Viking's playbook, where as teams such as the Colts and the Viking's will flourish.

If you have a star running back that you want to showcase, I suggest Run Heavy or the Dolphins playbook, which seems to be more run oriented than most.

And my favorite defense is 3-4, linebackers are essential, and great for everything, except covering the deep routes.

I use Lions playbook.