I try to help you and response your problems one by one:
"Slides end up being blank or sized incorrectly."
I think it's because you use different size of images or the SLIDER size settings is not correct. Of course I can help you to set it up correctly.
"There is a myriad of controls, many of which are disabled in the free version."
What do you miss from the free version? (Maybe we can improve the quality of it.)
"Can't find a way to remove a slide without removing all and starting over."
I think you deleted the whole SLIDER, but you want to delete just one slide. You can do this with the delete menu point. Here is a screenshot about it.
Please if you have 2 minutes share your ideas and frustrations directly to me and I will help to solve them or improve the plugin. Me email address: firstname.lastname@example.org
Have a great weekend!