Welcome to the wonderful world of Malazan.
Some things to keep in mind:
- Erikson will never spoonfeed you information throughout the series. Indeed, some things are more clearly stated than others, but overall the "fun" (with or without quotes) part of this series to find out by yourself what is the "truth" (with quotes this time).
- You will have some pretty well justified questions which will be answered a few books later. This is because you have to consider The Malazan Book of the Fallen as one book, where each respective book is but a chapter.
To your questions/comments:
Warrens are the realms that are most easily accessible by the human mages and it's the ones our common characters like Tattersail use during the first book.
Correct.
Elder Warrens are realms each accessible by one of the Elder Racers, like the Jaghut or the T'lan Imass.
How about we say that "Elder Warrens are realms most easily accessible by one of the Elder Racers"? wink
Holds, I have no idea what they are.
You are not meant to at this stage. You will get very clear* answers however on Book 5.
Chaos, I understand it is the... source where magic exists raw and primal? Anyone can access it, but it will make them crazy, like it did with Hairlock. Am I right?
Yes and no. We are not sure. Chaos is like high entropy magic. I guess one could argue that it is the "source" of magic in a sense but that is not entirely true due to various events in the later books which are serious spoilers so just be patient. But for now, your interpretation is not bad.
But, what are exactly the difference between Holds and Elder Warrens?
This will also be a lot clearer in Book 5 with subtle references until then. For now just have in mind that maybe some (not all) Holds are actually Elder Warrens or vice versa. There is a very good reason that both still exist, which you will also learn in Book 5.
I know that Warrens were somehow created by K'rul so don't be afraid to use that fact in the explanation.
The Warrens were created by K'rul, not the Elder Warrens. wink
Finally:
Also I don't mind some spoilers, because understanding this will help me enjoy the books much more, instead of trying to figure out if my understandings are wrong.
I really urge you to avoid spoilers. Trust the author. There is a reasons he's not telling you everything. It will pay off. Keep an eye for the details and keep reading.