Thanks for your feedback.

You have all made far more better comments and supported more people with your quick answers than my small list will ever do. Let's just say that sometimes I feel the need for a more complete list of hints to help me move through a game just to watch the story unfold, than to try building up Stats. So I am always in search for lists (far more organized than mine) to help me avoid bugs, find small twists of the games' story that I would had never given them a second thought while playing and so on.
Slug: There are people out there who provided so much information that helped me finish a game having far more fun than I would had if I had played the game completely by myself. (Let us just say that my imagination is not working at its best

)
As for the mule thing I used it just for testing purposes, without special items and somehow it worked (patched).
Carg: Thanks for your remarks and additions. BTW Do you mean that you don't save the game outside a city everytime you leave from a game session? I am not sure but the Leprecahn quest worked for me (patched) and my 4 members of the thieves guild were receiving 5000 of XPs everytime they entered the guild

BTW, I killed the short guy.
Wyv: Thanks.
Adam: I stupidly changed classes one too many times(had no vine spells over the 3rd level

), but at least I managed to end up having sun/spirit/moon/fiend/stone spells completed in different members of the team so I had only the cure poison spell limitation. You could always find me in the city after visiting the Serpent temple for a while

. (Ended with thit team configuration : Ninja (Sun/Moon) , Valkyrie(Sun/Moon/Fiend), Assassin (Moon/Fiend), Monk (Spirit/Stone), Warlock(Sun/Fiend/Moon/_Vine), Samurai(Sun).
Mortal (Aris)
PS: As always the use of English problem!