The magic rules in the supplements "Conjurers Guides" are not more "worked out" than the Swedish and US 1st. They are almost identical, but there are a few more spells in them, and a couple of new archetypes. The second Swedish version lacks magic rules and the US 2nd has some 2 or 4 pages covering the subject.
""Do yourself a favor and get the 1st Edition rules!"
It is not only condescending, but it also assumes that everyone thinks like and agree with you on this subject, something that has been debated on this very forum before, and guess what...
People think differently from eachother."
Well, you might think it is so, but that is also your opinion, right? Personally I see this as a piece of good advice and I have a hard time seeing the condescending part.
No matter what you and I think, the 1st edition is the most prised version of Kult, but of course, there are people of different opinion.
Finally, the 2nd edition might also be much harder to find. It does occationally surface on Ebay, but it mostly entail a much higher price than the 1st.