1 1/3 cup of sugar is 1 1/3 cup too much sugar for us in my house. We do NOT do refined sugar, BUT...an excellent substitute is honey! You could also use coconut sugar or agave depending on where you want to be on the glycemic index.
If you're worried about the alcohol in the recipe, it might help to know what its purpose is. Tequila is fun for the taste, but the alcohol is needed to keep the ice cream from freezing into a solid, unpenetrable block of avocado ice. If you don't like the taste of tequila, you could use vodka or rum. If you leave the alcohol out, you just need to let the ice cream sit out for about 30 minutes or so before attempting to serve. :D