Should i drive a 1967 mustang daily?
Go ahead and drive it daily, that's what these cars were made for. If you live in an area that you are worried about theft though, then definitely look into getting a security system, because classic cars are VERY easy to steal.
As far as safety goes, well you've got a padded dash and lap belts, that's about it. I think they also switched to a collapsible steering column in '67 to, so you don't have to worry about it impailing you in a head on collision. If you're concerned about safety then you can get some 3-point seatbelts, that will help a lot in a collision, considering that a lap belt will only keep you from flying through the windshield while allowing you to hit your chest or head on the steering wheel or dash.
These are really fun cars to drive, I love drive my '65 Mustang everyday and I wouldn't trade it for anything. These cars were meant to be driven so have fun and be safe, you'll love it.