For a vegan pizza, use a vegan cheese or omit the cheese entirely. There's a lot of deliciousness going on, so you won't miss it. If serving to vegans, please note that not all vegans eat honey (in the crust).
Make sure you microwave the beans before topping the pizza – this makes them not only more spreadable but also helps the pizza cook a little faster as the toppings are thick!
For a lighter pizza, cut the taco filling and beans in half (leave the tomatoes and cheese the same). As is, one slice is a pretty hearty serving.