Rotary Carburettor: Carried over from airplane engines when they were adapted for car use. For most hobbyists and racers this type of carburetor is fine, because it is simple to install and adjust. The throttle servo turns a "barrel", which has a hole through it, and this controls the amount of air going into the engine. A needle valve on the carburetor controls the amount of fuel going into the engine.

Slide Carburetor: a highly modified, car-specific type of carb that has the barrel of the carb slide along its axis, instead of turning. This provides a quicker response at the expense of a complicated set-up procedure. This type of carb will benefit a small number of racers and is not suggested for casual hobbyists. Two or three needle valves control the fuel intake at different RPM ranges.

Taken from http://www.rcpro.com/rc-dictionary.html#S

Standard and SG shafts are slightly different variations of crankshaft. Some flywheels & clutch assemblies require SG, some standard. Neither offers better performance than the other.

[link=http://www.wheelspinmodels.co.uk/products/nr94101.jpg]SG[/link]
[link=http://www.rceasy.com/wp-content/uploads/2007/10/15107_02n.jpg]Standard[/link]