I am working on a world (see this question) which I currently plan to have FTL via Alcubierre warp drive. I want to avoid the possibility of FTL sneak attacks so I plan on having something that prevents them from being successful in general.
My current plan is that FTL causes particles (such as thermal radiation from the spacecraft) to accumulate in front of the ship, with an energy that increases exponentially with time. Eventually, the amount of power required exceeds what the ship’s reactors can generate, and the ship must drop out of FTL to release these particles.
Additionally, incoming radiation is highly blueshifted to dangerous energy levels. Inside a system, the amount of particles (space dust, etc) is too high.
My evidence for these effects is The Alcubierre Warp Drive: On the Matter of Matter. Would those effects work as I am describing them?