Ok, I play on the EU server and my win rates are around 50% against all races (Terran is nearer to 60% but Toss is nearer to 40%) and so far to try and help myself improve I have tried to learn openings used by the pro's as they will get me in a good position early on.
Opening wise i'm fine for T and Z but unless P FFE then i don't know when to take gas, expansions, etc. This is becoming a problem as more and more P's are doing gateway expands (and other openings).
VS Protoss: Learning what to do against certain P "all-ins" and the timings etc for them. Often I lose to P all ins but if it is more of a macro game I tend to do better. Also against psi storm I struggle as my micro isn't good enough to split around it but I feel if I retreat I will have to take a worse engagement.
VS Terran: I usually do OK in this MU but I sometimes struggle with drops and also widow mines w/ bio can be hard if they micro well. As most people go bio I can usually be even in the early-mid game then win in the late game as I mix in Ultras which most Gold level players struggle with. Hardly anyone goes mech in gold but the games I have played against it i have used roach/SH/Viper to great success.
VS Zerg: I've become more confident in this match up since the meta game switched more towards mass roach rather than mass muta, and also as I play zerg all my scouting in this match up shows me info I can understand, so I can usually tell their BO and tech path just from a little info. So for this MU I think I need to just improve Zling/Bling micro so that I can survive early game then win with a roach push.
Hopefully this is helpful to you, if you want more info just ask and i'll try to give it to you.
Many thanks for your help