I'm skeptical, but I'll play along for a minute.

How do you get a 1000 ton (2,000,000 pound) engine into orbit? Does that include the propellant, or would you need to lift 900 tons of propellant, too? What about payload size and the size of the rest of the space craft?

How much propellant would you require to make one of your lightspeed trips to Wolf359 (constant 1g acceleration)? How big would the vehicle have to be to hold that volume?

How would you protect your vehicle from impacts with dust, solar wind ions, and micro-meteorites at high velocities? At just Earth orbit speeds a speck of dust will shoot through like a bullet. A baseball size rock would destory a space ship...

And, most importantly, with the fight against using RTG's, how are you going to convince the public to let you launch this thing loaded with 1000kg of radioactive material???

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...and we'll be saying a big hello to all intelligent life forms everywhere; and to everyone else out there, the secret is to bang the rocks together, guys...