Just a few things about the critical success table:
1. There are several very good effects on this table, which may overpower abilities which increase the odds of a critical (like the epic mastery feats). You may want to say that you only roll on this table if you get a natural 20 (anything else that is still a crit just gives the normal crit effects, not the table)
2. Some of these may be too powerful when used against PCs. For example the "automatic death" on a 20 essentially means that every attack has a 1 in 400 chance of killing the target outright. While this may not seem like much, it adds up - over the course of one level, say, you will have about 10 encounters * 5 enemies/encounter * 3 attacks/enemy = 150 attacks on players, meaning that the probability of a hit becomes reasonably high. Even some of the other effects, like "Finish Them", are very likely to be one-shots: a typical 1st level monster has a damage of 1d6+4, so Finish Them would result in (10*3) + (1d6+4)*3 = 3d6+42 damage which is very likely to one-shot a 1st level character. No player likes to be killed by a single lucky shot that they had no way of avoiding.