1. Why would the machines not kill Kyle Reese immediately, thus ensuring John Conner never existed instead of using Kyle Reese as bait to lure John Conner in order to kill him? There would be no John Conner to kill if Kyle Reese was killed.
2. Why would the machines only send 2 terminators to kill Conner, Reese and Wright? It's their central base for crying out loud. The placce should be swarming with all kinds of killing machines. But that means Conner would NEVER make it out..and thus no more happy ending or any sequels.
3. The Chances are very slim that Marcus's heart would actually be a MATCH for Conner...
4. WHy would the machines give Marcus a "free choice" to join them or not? They have a chip in his head! They can control Marcus's every move. Logically the chip would not allow Marcus to not remove itself.
5.Marcus was made into a infiltration terminator 20 years before the existence of skynet, conner, and ANY of the drama that would call for the need for one?

p.s. please dont make this into a racial thing but instead of the little kid..there should have been a dog. Imagine a dog doing all kinds of cool fighting tricks....