The expression "coked to the gills" is an expression that means the person is very intoxicated, either on alcohol or illegal drugs.
After her death, Victor seems to feel remorse and guilt because he is aware of what he did, because of the monster he created two family members are dead. Bu, at one point, these feelings turned into anxiety, it might give the reader the idea that he is impossible to figure out. This attitude might foreshadow what happens in Geneva and his decision of keeping the monster alive. It might be interpreted that more obscure things are about to happen.
There are many rising actions of Freak the Mighty. Some may include:
-Maxwell getting kidnapped by his father
-Freak dying
-Maxwell not being able to attend the funeral but that he is writing the book you are reading
-Freak and Max sneak out