my friend loaned me his acct over the weekend, so now that it's gone, i have time to comment that roaches are fairly overpowered in the early game. if you know the zerg's going roaches early, you pretty much have to be on the defensive as a terran or toss.
No, if your terran you block off your base then make a couple marines with a reactor, then a second barracks with a tech lab and mass marauders, marauders can kill 2 roaches per. Best defense in this game is the best offense/counter.
Zerg will always go to roaches, esp in lower leagues because people can get away with it against worse players. In the higher leagues you go zerglings to harass > roaches to hit the base > hydra/muta to harass gatherers > then counter whatever the other player has. Most plat players can kite with terran bikes and kill one unit at a time because of their speed. Siege tanks far away and bikes to harass units are win.
If your toss, mass zealots in lower league, get like 10 then attack if the other player hasn't. at that point you should have at least a cybor core and be massing stalkers and couple of those def shield units. Then you have a choice of either warping dark templar into the back of their base with a diversion up the front of the base or going void ray + zealot/stalker or doing colossus + stalker (or other anti-air).
You should always have detect units, if your terran, build the Raven and tech their laser shooting thingy, it rapes enemies because it doesn't allow them to get 20 missile attacks off. If possible when your terran, do 2 barracks, 1 reactor 1 tech lab at the start, then a factory and starport for siege and marine/marauder drop on enemy gatherers. If that didnt kill them either go thor + marauders or vikings, depending on counter.
Obviously these are rough diagram for play, and can vary depending on map and your style. My best suggestion would be for yall to learn how to kite with any unit, mainly marine stim-pack and med ship (if you can do that you can kite anything).