Well, I have some mods installed which also include:

Baldur's Gate Trilogy
Ascension/Redemption
Longer Road
Freedom Reign/Reign of Virtue
Oversight

But in the BG II and Tob part there are almost minimal to none new encounters, stores and other stuff.

Only the tactical encounters like Kangaxx and Firkraag and The Five from Tob seem to have some changes.

I also need some help in defeating Kangaxx Demi-Lich form, way to powerfull, tried almost everything.

Also when finally entering the Throne of Bhaal, I lose Imoen and have to fight her.

Also I can't make Jon Irenicus and Bodhi joining me.

What am I doing wrong?

I've never played Freedom Reign/Reign of Virtue, so I can't really help much there.

Have you both Redemption and Longer Road installed? IIRC, it should be one or the other. Chances are that something will go wrong if you have both installed.

From what I remember of those mods (obviously with the exception of Reign of Virtue), they don't add all that much to the majority of the encounters- much of the changes affect the tactical challenges.

To get Irenicus, you need his mask from Ellesime. For this, your Int and Wis should be at least 24, with both stats being greater than 10. Oh, and don't be overly polite. ;)

To get Bodhi to join you, you cannot be Good, cannot have Balthasar with you and must have a reputation of less than 12.

Well, that sheds some light on it, thx man

But how do I get the mask from Ellessime?