Is game in danger of eventually breakings?

[Escalon]

Game as a whole ? nah ? The Engine ? Yes and no, the engine is really just limping along on life support. But it will last until they try to push it over the edge and that hopefully wont happen.

[IronThistle]

99.9% of the time, when the question is "Why... ?!?"
the answer is "Money".

[Archeron]

Don't worry when they've reached the limits you can expect them to just recycle all sorts of assets and mechanics for another 10 years. We're more likely to get a completely different MMO than an upgrade to FFXIV's engine.