I don't know about the other modders, but I didn't start modding DotP knowing everything already... I learned many things from kev's mod, other things by trial and error, and there are a bunch of things that I still don't understand. There are no noob questions and this is the place to ask for help. Any help. I hope that those who feel too superior to answer to certain questions will need help sooner or later, and will find someone else who won't answer their questions.
That said, let's go with the answers (as far as my knowledge goes).
1 - I'm not sure if I understood this question... I think you already know how to make a free-for-all duel, right? Then just select the deck that you want to give to the AI. Be aware that if you use the unlocks in your deck, the AI will always use the "basic" version of the deck (with no unlocked card included). If you were thinking about creating a new campaign, I'm still missing some information about how to create it properly (see
here for details).
2 - You need to make an XML file with the localisation text corresponding to the deck name, and add <Glossary_Content/> in the INFO.XML file inside the <ContentFlags> tag. Unpack the latest kev's mod and see how he made GLOSSARY.XML and INFO.XML.
3 - You probably made some error in a card. When you exit the game (normally or with a crash), look if there's a MOTHER.TXT file in the game directory: it will tell you if there were LUA errors.
4 - I'm not using kev's mana tokens, but I noticed that basic lands always have priority over any other means of producing mana, and I think there's no solution to that.
5 - For the first token I had to create (for
Wurmweaver Coil), I made a copy of the file for the 3/3 Beast token from the Data_Core and edited it accordingly. Deck Editor Revised is a huge help for coding cards, but there are some things that you can make better without it.

Just remember to rotate the card image 90° clockwise if you are using a full "vertical" image for a full token frame (without abilities).
6 - As I said, Deck Editor Revised is good but don't rely on it for everything. For example, RW_GOLD (and also B_ARTIFACT for example) are included in the Data_Core, but not in the Deck Editor Revised.

Just look at the Data_Core's TEXTURES directory for yourself. If you use Deck Editor Revised, choose any frame for your card, then when the card is done, edit it manually and write RW_GOLD. You'll see a colourless card in Deck Editor Revised, but in the game it will be perfect. About card frames that are really missing (like every hybrid frame except for RW), you should use an image editor and do them yourself, maybe by copying and pasting pieces of existing frames (when possible). I did that for WU_GOLD_ARTIFACT using Paint.NET, and the result was quite good. Note that you also need to use a hex editor and change a value in the TDX file before using it in game... search on the forum and you'll find a topic by kev that explains it.