It's funny that you think a Lua/XML/SQL debugging process is simple enough that it CAN be explained in a quick bullet point format.
This is a programming language. Actually, it's THREE programming languages, each with its own syntax, although I hesitate to call XML a language.
It's not a quick and easy process, and there's no "Modding for Dummies" book for something like this. You need to read those introductory modders' guides (like Kael's), then learn more about the process, then try it yourself, then learn some more... and THEN, once you've done all that, you come on here and ask specific questions about what's wrong with your mod/map.
But fine, here's a very simple way to debug something:
> Start with what you KNOW works, i.e. the core game.
> Change one thing.
> See if it still works. If so, continue; if not, figure out what you did wrong in the above step and try again.
> Repeat until you're done.
If you spent days creating something without checking at any point along the way to see if it still worked, then it'll take forever for you to debug it and there's no easy way to make sure it fully works. Even after the crash bugs have been fixed, there can still be many bugs that cause it to screw up along the way that can't be easily caught, whereas a more iterative process would have caught those through their effects.
Now, if you're asking "how do I turn on the main debugging outputs", that's in your config.ini file; look for lines like "EnableTuner=0", for FireTuner, or the half-dozen or so logging lines for the text files. Set them to 1, and remember to load FireTuner up when you run the game.