Homebrewing Kindred for Spellcasting

For a couple days now,I've been trying to homebrew a subclass for the Kindred to make one that has Spellcasting, or at least more spellcasting than the Kindred class already comes with (basically making a Clan Tremere for my friend who's favorite clan that is for VtM). I have already tried all of the following:

• making a class feat called "Spellcasting"
• having a spell casting ability modifier (CHA)
• having "can cast spells" set to yes (and no just to test if that would work)
• applying an additional spell list (warlock)
• having spell prepare type set to half level
• knows all spells is set to yes
• spell learning style is set to prepared
• even threw a multitude of spells into the "additional specific spells" in the basic information section

But even still, on a level 20 test building character that I have, it only shows a list of the cantrips I put in the additional specific spells and all of the "learn" buttons are greyed out. So, I'm tjust trying to figure out how to 

a) make those greyed out buttons green

b) have levelled spells and spell slots