re: Poker & Chip Leader
Well for one thing this really depends on the situation. The size of the tournament and blind:stack size are the most important.
In a single table sng, you want to be pushing the middle size stacks. The short stacks are likely to call with a large range of hands. With large blinds, you should be more LAG, and small blinds, more TAG especially at lower limits.
In large tournaments, I tend to stay pretty TAG until the last 20% of people or so when the blinds get really large. Then blind stealing is very important for middle to large stacks.