The speed of light is a hard constraint, akin to the "clock rate" of the universe. It is the greatest possible change in spatial coordinates for a given unit of time. Thinking of it in terms of a speed or speed limit is less useful: it's a fundamental property of the universe. One consequence of this is that photons do not experience time in any meaningful sense between emission and absorption. Another more relevant consequence is that if any event (e.g. a spacecraft) does exceed the rate of event propagation (i.e. c) then you can construct a reference frame in which that event is observed to be propagating backwards in time. The speed of light and causality are fundamentally linked. If you want a universe in which FTL exists, you want a universe in which effects can precede their causes.
There is room for Einstein to be wrong. However, Relativity (and by extension causality) has been confirmed on every scale that we have been able to observe so far, from the sub-atomic to the intergalactic. Beyond that there is some gray area, but you'll note that we do not experience the universe at either extreme; whether or not Relativity applies to sub-sub-atomic particles, it certainly applies to us. It is an accurate description of the geometry of the universe at human time and distance scales, and at human energy levels, and at scales and energy levels far beyond what humans can harness. In order for what you want to be true, Einstein would have to be wrong -- not wrong in the sense that Newton was wrong, but wrong in the sense that the Flat Earth Society is wrong. And at that point we may as well give up science; if causality isn't true then empiricism takes a pretty hard knock.
You and Thanshin should quit spamming this thread with examples of human ignorance and rectify some of your own. Your argument is not very far removed from saying, "But we don't know everything about gravity! Maybe in the future things will fall up!". It's not entirely ludicrous to suggest that events can propagate through spacetime faster than events can propagate through spacetime, or that spacetime can be warped such that the shortest path between two points is less than the "true" distance, but it's at least 99% ludicrous, and championing the narrowest of possibilities while being ignorant of the (well-tested) established theory is not very rational. The geometry of spacetime is very strange and unintuitive, but if you're going to argue that it could be different then you should probably know how it works first.