Money is very important early, as early buildings can accrue a lot of advantage. Trader or Prospector for 3 or even 2 total coins can be a powerful move early in the game.
Try to pick roles that are better for you than everyone else - i.e. Builder when you have the most money, Trader when you are the only person who can sell, Mayor when there's an uneven number of colonists, or Captain when your opponents have goods they want to sell.
- Large warehouse is the most unused building in a game, there is little merrit to build it.
- University effective for the last round, if you build a large building and there won't be a mayor to activate it. And is you have a colonist on a sugar plantation and you build a sugar mill. Now you produce sugar.
- Guild hall is generally the best large building, it almost guarantees 7-8 points and 9-10 points are possible. All other can't reach more than 7-8.