I'm wondering about the advantages and disadvantages of genetic enhancements like making a designer baby. these types of things really interest me so please help. I'm also talking about animals and plants being altered genetically. thanks.

The problem with designing, say bananas, and then everybody adopts that strain because it has good yield, storage properties and tastes the best, leaving all the other strains to die off, then that leaves bananas in danger of extinction when a disease comes along that it has no protection against.  This is a true story. The moral of the story is: don't put all your eggs in one basket. The point i'm trying to make is that it can be very useful but pursuing some overarching eugenic dream for a species is short-sighted.

In addition, with crops there are relatively simple properties you want to optimize (often in terms of yield). Those are more often than not obtained by random mutation and selection (with exceptions). When it comes to designing complex traits, we still lack knowledge about how to manipulate the system to yield the desired results (and in some cases, clarity regarding what the desired results are).