How can you grieve for someone you didn't like, in the end?
Somehow... that natural love and bond of family relationships - find a way. No matter what and no matter who, good or bad, there's always that feeling that you know they are family and you tend to love em all the same.
I concur with what you said about remembering the good times instead of the bad ones - that's the best way to honor a person whom has passed. I'm sure your cousin would've liked that little forest goodbye you gave him very much.
I send my love and condolences to you, your family, and his family too. Take care...