1) The guide was written more than 6 months ago. If you're running a later update of Android, or not the current Framaroot. it may not work. (Since I don't use Framaroot, I won't comment on what you're doing wrong - I have no idea.)
2) Rooting the phone uses storage, it doesn't add storage. The only way rooting can be used to free storage is by removing system apps you (and the phone) don't need. Remove the wrong app, though, and the phone stops working.
And it's only a temporary measure. The tablet has 8GB of storage, about half of which is taken by the ROM, and the phone needs about 500MB free, so you have 3.5GB to store apps. You can probably gain 500MB - maybe even as much as 1GB - by removing Verizon junk, but 4.5GB of storage these days is tiny now. It was a small tablet when it was released over a year ago, so use it for what it was intended for - pictures, videos, music, documents. They can all be stored on the external SD card (and it will take a 32GB card). It wasn't designed to run a lot of large apps on.