Ryan,

Yes, although you won't be able to use any of the API for the Document Libraries because your license doesn't allow it.

You might look into the ROI in purchasing base + creating your own VS. purchasing Ultimate and having the functionality already there. How many development hours might you have invested (requirements gathering, development, project management, testing, deployment, etc) by attempting to save a few extra bucks

Here's an example, say the average employee makes $50k per year + $25k for benefits package for a total of $75,000/yr. Now take that one employee and dedicate them 100% of the time on this project for 3 months. By the time you spend 3 months (probably be longer) you've invested over $18k ($75,000 / 12 months = $6250 * 3 months) of this employees time into creating something that would have initially cost you an additional $3500 (at least until 12/31/2013).

Yes doing it yourself you can customize it as you wish but you can do that as well with the base controls Kentico has already developed. If you don't find something is working as expected create a copy of it and modify it as you wish. The nice part is all the base functionality is already there.

Brenden