You account for thrusters failing by having regular maintainence and testing and additionally deploying multiple independant examples of. To assume a toroid/cylindrycal design, these would sensibly populate the perimeter and slight rotation - which is more than likely to be going on anyway to provide for gravity - brings another thruster into line with Delta-V.
Severe solar activity is likely to be rendered futile by the radiation shielding, there's a reason I'd specified five meters thick NiFe skinned in 6cm of titanium. It's called density. If it's getting through that, then it's also wiping out all life on Earth, as after magnetic dispersion a couple of miles of air has significantly less density than five meters of NiFe, I'd not imagine much to get near, let alone past the 6cm on the other side of the NiFe, the outer hull, the inner pressure hull or near the habitation zone. Same with xrays, gamma rays - wave and particle it should stem the lot.
Design can account for more than some, it can almost eliminate the possibility. What remains is a factor regardless of if you're on a station or not. On the whole. Hence "about as safe as a terrestrial location". Being in a much more controllable environment, a lot of that can have something done about it too.
Factoring in that threats can come from (almost)any direction would possibly be why as well as "left" I'd also suggested adjusting velocity as this would hold potential for the easiest way to be in a different point in space in a more appreciable time. You can just simply plan for everything - how do you think it happens now? You don't wait until after the event. Unless you are eager for failure. We've also an advantage as there's a massive list of previous mistakes to learn from.
There are very few unknown variables with such an operation, at least to those who would take the time to pay attention to what is actually involved. There's a large number of them, certainly, but they all resolve. Most easily as these problems have all been solved before. Seriously, the largest headaches are things like thermal dissipation systems on that scale. Most of the unknowns are centered around the human element, and not the station structure or biostasis aperatus. Or for several generations down the line.
I'm not underestimating how deadly space is, and there is no false sense of security. I just don't panic over easily solved problems.