In the very beginning, Karen is seen alive in the coffin; but in the original film, she is shot by silver bullets, which would kill her.
When Christopher Lee reads from the Book of Revelation, his Bible is opened near the middle, but this book is the last book of the Bible. Visually, it probably wouldn't have looked as good if the book was opened to the end, plus balancing it in his hand with all the weight on one side would have been difficult.
The rifle that Ben was given by Stefan in the church, Stefan telling him that it belonged to Vasile, appears in the following forest scenes to be the exact same rifle Ben was carrying into the cemetery in L.A. earlier in the movie.
Ben starts driving the car after Stefan stabs the woman lying in the road, not having been shown to have removed the body from the road, but he appears to drive straight ahead instead of steering around the body.
When Vasile eliminates the sentry, Ben is talking to Vasile in a normal voice. Considering they were close enough to the sentry that Vasile, a dwarf, was able to successfully dispatch him by way of throwing a knife into his chest, the sentry ought to have heard Ben's undampened speech.
It is questionable whether or not Mariana, Stefan, Ben, and Jenny could have obtained the travelling papers necessary to enter Communist Romania on such short notice during the 1980s. The decade was marked by an increased paranoia from Ceausescu and a proportionate increase in the power of the Securitate secret police.