I think it is totally reasonable for you to try and create a business out of this - if that's what you want to do.
You ask an interesting question:
How can we achieve our objective of a commercial FOSS offering that will preserve the value of open code and open data to licensees, without having to fear that someone will copy and squander our investment?
The answer is simple. You can't.
The database is under the GPL - although is now under the AGPL I believe - that means anyone can copy it and resell it (as long as they publish the changes & comply with the licence).
So, anyone can take your data - and reuse it for free - this means that you can only compete on value for money through superior customer service and professionalism.
Essentially, because your data is freely available, you have to compete on service. That means a slick website, guaranteed SLAs, versions in as many different programming languages, working with CDNs like Akamai, show a long term partnership plan to continue getting data etc.
Make it so that it is easier to use Scientia than to use the competition. While people like me are quite happy to manually compile stuff, code around API limitations, etc - most businesses want an "out-of-the-box" solution which doesn't require them to think, and comes with support.
You can't stop other people from (legally) copying the WURFL database. So you need to decide whether Scientia will be able to recoup the investment. It may not be possible. You may have to be satisfied with being one of many DDR providers - even if it isn't profitable.