1. a mutation which produces a duplicate gene.
2. that the duplicate gene does not hurt a vital part of the genome.
3. that the duplicate gene gets spread through the species at chances of 50% survival at each generation (note no selective advantage since the gene is just a duplicate at this point).
4. that the new gene acquires a mutation and then goes through 3 above to spread itself throughout the species again (again no selective advantage yet).
5. that it hits upon the correct helpful mutation by pure chance while going through 3 above after each try.
First off, #2 touches on why the presence of junk DNA helps facilitate macroevolution: If the 73% of our genome that isn't coding nor introns really is junk - in the sense that the specific sequences don't affect the cell's metabolism - then that gives a random gene insertion a 73% chance of not clobbering an existing gene, & therefore not harming the organism in any way.
I think I tried to explain to you before why your #3 is all wrong. Let me quickly try again. (And godel or longshadow or some other mathematician will have to put some real math to my assertions here:)
The chance of any one allele (new mutation in this context) being passed on to a specific child is 1/2. The chance of the same allele being passed on to the second child is also 1/2.
The chance of at least one of these two children getting the mutation is 3/4. With 3 children, it's 7/8. With 8 children it's 255/256.
Put another way: The number of children that will have this new mutation will be (on average) 1/2 the number of children! If the mutated parent has 6 children over its lifetime, then the mutation will spread to three individuals. If the parent has 50 children, then this mutation will spread to 25 individuals, where before there was only one! There is no problem spreading a neutral mutation from one to several individuals.
So your #3, which you think is such a daunting barrier, is no such thing. This makes your #4 & #5 evaporate as well.
No, you are absolutely wrong and if you look it up instead of looking for excuses for you phony evolution, you would stop repeating that nonsense. The chances are 50% because there are two alleles and by all scientific research either one is as likely to be chosen as the other. Since a new gene would have no allele it would only have a 50% of going on to the next generation. If it survived, it would only have a 50% chance of continuing to the next one and so on until such time as it had spread enough that sometimes both parents would have such a gene, so stop talking garbage and start facing the truth. You must remember this is a new gene - no one else has it. The chances of its spreading are very slim indeed. Because there is no selective advantage in a useless gene the chances of its spreading are always the same 50% at each reproduction. Such genes dissappear from the population for the same reason that any gene which which is detrimental (and that is the basis of your stupid evolution) dissappears if it goes around killing those who have it - because the rate of reproduction of that particular gene is less than that of the population at large. Even if you start with a population of one million with half having one gene (call it A) who reproduces at 100% and the other half which reproduces at 90% of the rate of the first gene (call it B), gene B will almost dissappear and be in less 1/1000th of the population in a mere 100 generations.
And no, 4, 5 and 6 do not magically dissappear as a problem to evolution no matter how much you would like them to. The one chance of finding a correct series of mutation at random (because again the gene is non functional) is astronomical. In addition to which, regardless of your nonsense about 'inefficiency is good' carrying extra baggage which does nothing is never beneficial, if you don't believe me, put ten pound weights on your clothes and start carrying them around for a while and let me know how much benefit you derived from it.
Put another way: The number of children that will have this new mutation will be (on average) 1/2 the number of children! If the mutated parent has 6 children over its lifetime, then the mutation will spread to three individuals. If the parent has 50 children, then this mutation will spread to 25 individuals, where before there was only one! There is no problem spreading a neutral mutation from one to several individuals.Just wanted to see this again.
The answer is no, drift at one generation is always around the allele frequency of the previous generation only; and allele frequencies in more ancient generations are totally irrelevant. THERE IS NO TENDENCY TO RETURN TO ANCESTRAL ALLELE FREQUENCIES.Genetic Drift: The Role of Finite Population Size.