Yes, it's spelled ambient. Ambient occlusion (AO) doesn't really makes sense for a mesh that has no real indentations or overlaps. AO is basically a way to add soft shadows to the indentations or crannies of a mesh. The ribs on a barrel don't really have enough detail to warrant baking a map, just paint soft dark lines on…
1. for most game modelers it easier to create a lowpoly model first, then duplicate it and create a high poly. don't be stingy with the high poly! you'll want that detail when you bake a normal map. 2. if by the top you mean the top rim, then its really up to you. of course the more geometry the better. but this all really…
#1) It really depends on the object. But for most of what I do, EQ is dead on. High first, low poly second. If you do low before high there is so much that could change. It leads to a bunch of remodeling and re-unwrapping, just a pain in the ass. Often in the case of environment work depending on how you maintain your…