Another area of failure is the state of the land of Canaan.
Rohl would have it that the events that appear in the Amarna letters correspond to the reign of Saul, making rather questionable identifications of people named in the Amarna letters with Biblical characters.
As Steelclaws points out, at the time of the Letters, Canaan was still at least nominally subject to Egypt. Labayu - who Rohl identifies with Saul - acknowledges this overlordship and claims that his father and grandfather before him were loyal subjects of Egypt (suggesting to me a hereditary monarch). There is an Egyptian commissioner, Addaya, with a guard of soldiers in the region and the local rulers pay taxes and tribute to Egypt.
You would think that the Israelites would have been rather sensitive to Egyptian rule, given the Exodus story, but the Bible has no mention of this at all.
The main conflicts at the time are between the Canaanite rulers - Labayu is pegged as a particular troublemaker - and the 'Apiru. The 'Apiru are a socio-economic group, probably best considered as bandits and mercenaries in this context. There's no mention of the Philistines, although the Bible reports conflicts with the Philistines even in the Judges period, and Saul was killed in battle with them (Labayu is killed by the people of Gina, thought to be modern Jenin). Egyptian records don't mention the Philistines until the reign of Ramesses 1
Going with a more conventional chronology certainly solves the problem of the Philistines. The Merneptah stele - the first mention of Israel - identifies Israel as a nomadic people and is thought to correspond to the Judges period - this is flat out impossible in Rohl's chronology. The conventional chronology fits better with both the stele and the Biblical references to the Philistines.