wow.. man its been a while since i last touched SC:BW.. :P think its been nearly 5 years.. was a fanatic back then... nearly everyday at SS15 CC.
FYI, all those korean gosus dont cheat.. they're just that good... but i've also played against top ranked malaysia players.. even the malaysian champ... they're also just as good. Ask them and they'll tell you the same... basic will always be to learn to manage the economy part... then on to troop production.. then onwards to rushes and so.. but what differentiates a gosu and a normal player is the knowledge on troops stats.. i mean it comes naturally to them.. they see you using a certain strat.. they will come out with the counter just as easily.. i've seen players with reference charts stating the number of minutes needed for a certain rush... if it passes a certain time and if they havent seen the enemy attacking, they will prepare for the next strat.. crazy man those guys...
anyways, my favourite race is terran. pretty balanced, has the best defence for turtling :P just that its need more micro management then the rest. imho zerg is one of the easiest race to use, cause their units are expandable.. they're expected to die.. compared to the protoss, where you really need to maximize the portential of every single unit...coz they're just plainly expensive..
based on my experience, i think there are certain advantages when using a certain race against another:
Terran > Protoss > Zerg > Terran
I'm not saying its a total loss scenario.. just that they have certain advantages. Terrans with EMP usually rapes protoss but succumbs the swarming of zergs and dark swarm. Protoss will have an easier time dealing with the swarm with the help of shields and high damage. Even gosu's admit it, if they face a chanllenger with the same skill level they usually go for the race with the advantage over the race that the challenger choses. just my 2cents :P