I am looking to create a world with temperatures to both extremes, multiple good and evil savage biomes, preferably with one large continent and somewhat livability for civilizations. If anyone can point me in the right direction with the Advanced Parameters, I think I can figure out the rest, I think my problem is with the meshing. Thanks!
So, in terms of the mesh, a larger mesh size (16x16 verses 4x4) gives you a finger grid (smaller grid squares). I'd say if you're looking for real extremes, set the temperature mesh size to 16x16 or 32x32, with a world of, say, small or larger, and then set the weighted values to 1/0/0/0/1 (that will generate only extreme cold and extreme hot, with the bits in the middle smoothed out on a gradient). You can do the same for savagery.
For good and evil, I don't think you can control those directly, but what you can do is turn up the minimum evil squares per small/medium/large region and the minimum good squares per small/medium/large region. That will give you a better chance of your evil-ish biomes becoming evil and so on, I think. For
multiple good and evil biomes, the best you can do I think is make a patchwork with a more biomes than usual, and then just by the law of averages you'll get more good and evil biomes (along with more neutral biomes). You can do that by turning up the variance on things like elevation, drainage, and rainfall, and then turning up the maximum number of sub-regions if you start getting rejection spam.
For livability of civilization I think your best bet is turning down the number of beasts and megabeasts. To get it all on one continent, I'd raise the minimum elevation - anything under 100 will be ocean. If you're using PerfectWorld, you can adjust the % below sea level and preview it to make sure it looks good.