Hi Corey,
You can choose to use a database specific version of RedBeanPHP, like RedBeanPHP-Mysql to reduce the memory footprint.
I don't think you can omit a large number of classes, there is not a lot of bloat in RedBeanPHP, so if you use the DB-specific editions,
you are very much using the slimmest version you can get.
cheers
Gabor