When Reb escapes the biker hangout, he launches over the police blockade in what is clearly a dirt bike. After he lands, the scene cuts to a wide shot of him admiring his efforts and continuing his escape on a cruising-style bike. There is no evidence of him switching modes of transport.
Reb escapes the biker hangout by launching his motorcycle over the cars in the police blockade without the aid of a ramp or other device to render him airborne.
The Krugerrand is an once of gold. The "coins" from under the wet bars are way too big. An once of gold is slightly smaller than a silver dollar.
When the wedding guest is shot and falls face first into the cake, the extras in the background just stand there, the slowly saunter off, making sire not to spill their drinks.
Reb puts the rifle together, puts the clip in. He then shoulders the rifle and takes the shot. He never puts a round in the chamber.
Shotguns would be useless at more than 15 - 20 yards. A SWAT team would know this. Also several times they have sound effects of shots being fired, but there is no recoil.