Changing "Read More" Text

[mousie]

I've noticed that when the excerpt on my homepage is under a certain amount of characters, it says "Read More ->"
If it is over a certain amount of characters it will either show "..." (the top 2 category boxes) or "[Read more of this review]" (the bottom category box). I have a few questions about this.

1) For all category boxes, how do I change "Read More ->" to say something else?

2) For the top category box, is there a way to make "..." not show up at all?

3) For the top category box, is there a way to make "..." become a link, as if the amount of characters are under the limit?

4) Not to sound confusining.. but for only one category box (top left), can I change "Read More ->" to say something different (question 1) and then make that text be a link to something different? (i.e. not a link to the post that the title and thumbnail will be directed to).

Thanks.