well, whatever method is chosen to implement the test, the result should be a warning box with a "yes, I understand why the test failed, please don't bother me about it" option. advanced users can come up with all sorts of interesting configurations that don't meet the pre-planned wizards and tests.
regarding the usage of the terms "Bridge Mode" and "Router Mode", yeah, you're right, it's something of a misnomer. But it's convenient short-hand to describe the simple 2-interface UT that is most often discussed here. Multi-interface UT's do almost always have both routed and bridged interfaces, but those are also much harder to plug in backwards without knowing it - a lot more breaks right away when you do that. And you have to admit, a 2-interface UT with the interfaces bridged behaves very differently than a 2-interface UT with routing between the interfaces. Finally, the UT documentation, such as it is, makes clear that "Bridge" and "Router" are the two basic deployment methods (excluding the deprecated Re-Router installation): http://wiki.untangle.com/index.php/Introduction