spent some time on the Lenovo forums, and found that they really don't want us to change partition sizes. doing so causes their recovery utility to not work.
so it looks like ill be keeping my data on the C drive together with windows, and just backing up regularly to an external hard drive. I could set up partitions as I like but would need to have another windows 8 re-install option, which is a project for another day.
It's odd that Lenovo is not providing a proper place to store data. It's nice that I have 800 gb free, but why does it have to be right there next to the Windows system?