In many cases it is worth to invest into middle. That's true that you get less gold for middle kills (with exception of units killed by heroes), but if you are really owning middle you can farm up to 3 players, which gives you much more money than a single lane. Plus you deny gold for your opponents, what gives you gold advantage over them. Speaking about neutral buildings: their bonuses from them are moderate, and only gold mine gives a decent amount of gold, which may be worth focusing in on the early game. I know that's a rather delayed response, but maybe will be usefull for somebody :) And remember - every game is different and requires a different strategy!

it's still active on all the original servers! whether or not you should buy it though depends on how nostalgic you feel about the game :P there are a decent amount of new maps being made and a decent amount of people still playing, but it's not a huge number either way

Terry Lockwood he likes to pick different bonuses, plus that tactic doesn't always work