Plot hole: Echelon controlled satellites hit targets on Earth with pinpoint accuracy. A lot of them involve creating storms to ravage an objective. One of them is started over 18 hours away from the target (how they know is another mystery), but this is what gives the characters time and allows the movie plot to continue to the end to defeat Echelon.
Plot hole: The past has changed, but Kyle Reese is evidently the same one who was sent to protect Sarah Connor. In "T1", he explains to her that the T-800 CSM-101s are new units, with real human tissue, difficult to recognize, and that he had to wait for the cyborg to approach her before he could identify it; this means that he had never seen a T-800 that looked like Arnie. In this film, however, as soon as he sees the T-800 "Pops", he shoots it and later claims to have never seen an "old" Terminator. (00:28:31 - 00:31:36)