As evident by the replies there is no uniform answer. I would advice to look in game for players that consistently do well (note: this is not necessarily the ones that are on top of the score board but it can certainly be used as a guide) and take special note of their advice, since chances are those will be more accurate. Secondly if you find a few players that do well, try to find one with a similar play style like yours and refine your set of advice further using that. There are many styles of play and you will need to A) find good tactics over all and B) find good tactics for a play style you enjoy and do well in.
Also regarding legging, without going into a balance discussion on gameplay there are a few things to keep in mind about legging that is causing issues at the moment. Due to the way mechs are set up and engine limitations legged mechs can end up covered by terrain, being very difficult or even impossible to hit while still being able to return fire. This can of course be annoying and if this happens to you and people start screaming obscenities then you know why. Could be a good idea to exit the mech at that point
. Also even when the general consensus in a given game is that legging is bad certain mechs are still bound to get legged frequently by pure chance. The Owens for instance is notoriously easy to hit the legs by mistake.
/Merf - Some problems have many solutions
