beyondconfused,
1. You can play without using the tactics menu at all. Its purely optional. Ignore it if it makes you so retarded angry.
2. The strategy guide does explain how to use it. The booklet does only brush up on it. The in-game codex system breaks down how it works.
3. No one can give you step-by step instructions. You taylor it to your play style. The tactics page is for setting up "AI" for teamates. It decides what they will do and when.
Example: if you set >50 Health then pick the healing skill, that person will heal at around 50% if they can. You can go further, you can define the target of the spell. You can do this for skills as well. Its essentially a series of If/Then statements, a very basic version of programming.
4. Its purely optional, and its not designed for everyone to use. I personally found it pretty easy to use, however the default ones it gives for the AI work well, so you should never have to touch it.
5. Return your game if you want. Your loss. The success of this game is not going to tank because you returned your one copy.
You probably should go back to playing counter-strike. Just some friendly advice.