Yes, we share common DNA or similarity with all species, this genetically points towards a single point from which the tree of species sprouted. But, % of similarity is significant. While we share 97%-99% DNA with monkeys, it won't be the same for cats or whales. Our lowest DNA similarity is in fact with marine organisms, even then our similarity is in percentages of 10s.
1. The missing link is that point where life started, either as a cell or according to macro evolutionists, as a complete organism. It is true that we're not absolutely certain that humans evolved from monkeys, but the evidence of genetic similarity and transitional fossils, as well as fossils of Homo Genus point towards that direction.
2. This actually is, and also isn't an anomaly. Other species of humans did exist back in time, Neandtherals and whatnot, and through dating techniques, we know how long they survived. However what we don't know is why only the Homo Sapiens came through while the rest died out, point to note is that we did evolve in later.
3. Evolution isn't accepted by Christianity faith. But it has leeway in Islam, there are numerous books written on the subject matter.
4. These artistic impressions are based on the transitional fossils and fossils of other members of the Homo Genus.
5. I don't know what books you read, but as far as I remember, our books never called certain parts of the human body 'useless,' just simply that we haven't found their function yet.