I am left handed with a long gun (Left eye is my master eye) I have owned and used a M1A NM rifle for over 30 years, she is still a great favourite especially as she is ideal for a left handed shooter. The safety and mag release are ambidextrous and the charging handle on the left is ideal for us. Never a problem with empty brass hitting me. An M1A (M14) talks to you, you have to tune your brain to listen and trust yourself to act, she sounds different (even with ear defenders) and feels different when you have a malfunction or fire the last rd in a mag, this was in the UK in the old days with 20 rd mags. I never could count to 20 under stress! I expect one failure to feed, or stove pipe etc per 1,000 rds and been left handed always allowed me to glance in the action with out moving the rifle from my shoulder to confirm what, if any, action was required, this was a real advantage with the fast snap shooting on timed exposures that we often used to shoot.
Push button safeties: I have mixed feelings about reversing them, if you do, you may handicap yourself if you pick up a standard gun and a stranger could be unsafe with yours. I have learnt to live with firearms designed for right handed shooters and surprisingly have very little difficulty.
Those of us who are naturally right handed but left eye dominate, we often have a distinct advantage while carrying out some drills and reloading as we have our most dextrous hand (right) for performing the reload. I have found this to be very true with single shot and double rifles.