If Natural Selection is seen as similar to Artificial Selection (as Darwin did), then there is intelligence and purpose involved in it.
Yes it is similar but natural selection needs no intelligence because what does the 'selecting' is just the environment.
If NS is seen in terms of Neo Darwinism, it is just a metaphor.
This is simply wrong. You've misunderstood. Read any decent book on the subject, go to any reputable website about it, and if you pay attention, you will see you are wrong. I'd post some links now but from previous experience you simply won't listen.
Once we accept that Nature could be Intelligent, the intelligence need not be 'external'......it could very well be internal. Intelligence could emanate from within the DNA leading to genetic variations.
You have still not given any reason for anybody to accept this intelligence.
Genetic variations can be of two kinds...random or specific adaptations to suit the environment (as in Lamarckism).
Nonsense. Genetic changes (mutations) are all random. Some of them happen to suit the environment and then, exactly because they confer and advantage, in terms of survival and reproduction, those individuals who have them survive and reproduce more than those without, hence the mutation spreads through the population.
That's natural selection - a real process.
This is where Intelligence comes in......
Intelligence is not required. That is, it's not required for evolution to happen, it is required to see that natural selection is absolutely real, isn't a metaphor, and explains how evolution works without any intelligence.