This is my knowledge from what I've learned and experience so please feel free to correct me if some info isn't correct
I'm going to correct you but don't take it the wrong way.
1) Boxer is the primary primer used in modern ammunition. The reason is it is far simpler to remove the primer for reloading purposes. Berdan not burden are not common and pretty much not used in US manufactured ammunition.
2) Modern smokeless powder really isn't corrosive, but if residue is left in the barrel it traps in moisture. Real black powder is the corrosive stuff you have to worry about. If you live in an area with high humidity then you'll want to clean your barrels more often than I have to in Colorado.
3) Is correct however, in some cases aluminum is used as well for the cartridge case though usually not for rifle cartridges.
4) There are far more bullet types than you mentioned. I'm not sure what you mean by round? Round nose (RN) maybe, these aren't found in .223 very often. HP, FMJ, SP (soft point) BT (ballistic tip), BTSP (boat tail soft point), BTHP, and VLD (very low drag) are more common.
All primers pretty much anymore are non-corrosive, unless you are shooting some old military surplus ammunition made in some third world country.
Any powder can leave un-burned residue in a barrel, it depends on several factors. However slow burning powders in short barrels will leave the most residue.
Not completely correct. Don't confuse ejectors with extractors, extractors are what grab the rim of the cartridge and pull it from the chamber. Once free of the chamber the ejector throws the cartridge clear so it doesn't interfere with the next round chambered. Usually steel cases extract as easily as brass cases as long as the rifle is kept fairly clean.
FMJ are not a common bullet for small game, but for target and military/LE ammunition. Depending on the bullets purpose any of the bullet styles mentioned can be used for hunting, target, or defense. Most manufactures will tell you if it is a target, varmint, hunting, or defense bullet on their web pages.