The most important way to minimise risk in the case of an engine failure is to practice engine failures. Often.
Yes, Me too! I try to do a power off landing from downwind at least every other flight, just for practice. You can't usually do it at an airport with traffic, but any time you have the circuit to yourself, practice!
Altitude is potential energy, and the more potential energy you have, the more options you have. Speed, on the other hand, is kinetic energy, and the more kinetic energy you have, the bigger a hole you make when you hit the ground.
Yes and no... If you have too much speed as you approach to flare, you can bleed it off with drag, or at worst, touch down parallel to the surface too fast. If you have too little speed when you approach to flare, you are going to make a mark when you hit the ground. Considering clearing the proverbial trees at the departure end of the runway, I'd rather clear them by a few leaves with more airspeed, than clear them by 100 feet at Vx. If the engine were to quit a hundred feet above those trees, I'd waste that 100 extra feet jamming the nose down trying to accelerate in the glide to a gliding speed sufficient to flare. It would be a very unstable approach to a gliding flare.
Many pilots would tell me they always wanted to get well above Vy after takeoff for various reasons - time to respond to an engine failure, keeping a distance above Vmc, etc.
I agree with V1 Ooops, If you're going to loose an engine in a multi engined airplane anywhere near "low altitude", you'd rather be right around Vy/Vmca, Slower than Vmca is simply dangerous. Faster than Vmca means that you'll have a lot more drag to overcome from the failed engine as you feather it, and it may be difficult to maintain directional control as you slow down to Vmca.
Near the ground, fly the speeds in the POH!