expansion?

I was looking at this guy's idea(link here) and I think that(more or less) it could be plausible... the problem of deep space travel for humans doesn't seem right but it looks like a good idea for finding a target planet, then working on the problem from there. Though I do not know much about the topic myself, perhaps more research could be done on this?

Sure, certainly an interesting idea. He seems to not have considered necessarily how to get to these target destinations. As you're probably aware, nothing can go the speed of light or faster. So limited to just under light speed, the closest star system, Alpha Centauri, is five years away =(. Of course, hauling humanity would need a rather large ship, or ships. Then there's the problem of power sources, and such.

By the time this is feasiable, it'll be thousands of years in the future, and we'll for sure have found a good planet to live on.

The idea is interesting; but I don't think it is viable as is. Sending out just a few humans alone is not viable either. Perhaps doing both together in tandem is more reasonable, and we would have less of a problem with culturalization of the next generation. Sending out a large population of adult humans seems silly in comparison. Robots could help, but there would still be a few humans always around for culturalization of that new space going generation. We don't know the long term physical effects of such travel on such a population of humans. That will remain an open question for quite some time. I'm sure there would be consequences, but these problems might also be mitigated through continued research.

We modify the scenario where there is a continuous supply of a few embryos being grown and then born in flight. Once the ship has arrived at the destination, there would be plenty of genetic diversity to make a viable population with a link to traditional human culture.

Anyway you look at it...it seems to be a difficult proposition to sell and make work. Regardless, the technical challenges are enormous. But such modifications as discussed in my post probably present fewer ethical challenges, in my humble opinion.