No mention yet of how a dual axle fights. When turning, since there is no steering axle, both axles get torqued. the tires on one axle will bend inwards, the tires on the other axle will bend outwards. Look at a parked dual axle and you might see wheels leaning different directions. When pulled straight forward a few inches they will straighten back out.
This is not a big deal unless you try to move the trailer by hand (or with a few friends) and cannot steer it as the wheels have to break loose sideways for the trailer to pivot side to side.
OR if you have the tongue on a wheel jack and try to push it side to side like when hooking up to tow ball.
As for blowouts, unless the tire blows completely off and is gone you will not want to drive with a flat at any speed over 3. The shreded, or soon-to-be, tire will flap around and damage your trailer. Change it asap. You can drive on a flat be it a dual axle or a single axle just the same. That 5 inches of distance the rim is suspended above the ground is not going to flip any trailer over of cause any handling issues when there is no aired-up tire holding it up. The handling issues are the flat/airless rubber pieces, not the angle.
Setting up 4 electric drum brakes properly is much more difficult than just two. You can run just one axle with brakes on a dual axle trailer though, but there is less braking available as those two braked tires have less weight on them.
If you go off road then a dual axle trailer has great advantages you will never need on pavement. This is another topic I think though.