I would have a hard time choosing one of those as well, although ecumenicism is definitely a problem of today.

I wonder if part of the problem is determining what are roots problems and what are symptoms of these root problems.

For example, couldn't you argue that Arminianism is a root of the seeker-sensitive problem and the Open Theism problem? How many Reformed seeker-sensitive churches do you know of? Or, how can one be an Open Theist who is not also an Arminian?

And isn't universalism really pluralism taken to its extreme, and isn't the emergent church seeking to find a middle way between pluralism and absolutism?

And couldn't you trace ecumenicism in part to either seeker-sensitivity or pluralism?

True godliness is a sincere feeling which loves God as Father as much as it fears and reverences Him as Lord, embraces His righteousness, and dreads offending Him worse than death~ Calvin