Re: Why don't the Borg use genetic engineering and cloning?
Eh, while VOY was not perfect with the Borg I've seen nothing to suggest the Borg weren't already assimilating by the time of "Q Who?" The Borg Queen certainly supported this assumption in FC, and given how long the Collective has been around (thousands of centuries, according to Guinan), I think the most the D could have offered them was a new target.
"Q Who?" specificly suggests they were only interested in technology. They didn't start asimilating until BoBW, after they met the -D.
For me, and for many of us, the future is now in the past.