I agree (about the Ark.) I also agree the tv show - while it creeps along at pedestrian pace - holds some intrigue; it has the potential to change the history of western civilization. Will it? Probably not, but...
I panned the idea of a pre-Columbian Templar visitation, but the discovery of the Roman pilum did raise an eyebrow. That is just the sort of Christian icon that the Templars valued; like the Holy Grail, it touched Jesus' body and would have held His blood. Whether it really was the spear that pierced Jesus' side, to the Templars it would have been worth possessing. Not conclusive, but suggestive.
Given the date of the logs found in Smith's Cove, it would seem some connection to the American Revolution is suggested... but why Oak Island? Perhaps some 'French treasure' was cached there.