Okay, I just found out the source for the smash-merging of the Richard Camvilles. Wouldn't you know, it was Sir Bernard Burke his own damnself! (Earlier editions of Burke's Peerage were error-riddled because he was none too careful about sourcing his information - there have been gradual improvements over time.)
This appears to be verbatim or closely paraphrased from Burke (almost certainly an older edition):
"In the time of King Stephen, Richard de Camville was founder of Combe Abbey, co. Warwick, and was one of the witnesses in the 12th of the same reign [1147], to the convention between that monarch and Henry, Duke of Normandy, regarding the succession of the latter to the crown of England. This feudal lord appears to be a person of great power during the whole of King Henry's reign, and after the accession of Richard I, we find him one of the admirals in the expedition made by that monarch into the Holy Land. He was subsequently governor of Cyprus, whence he went without the king's permission to the siege of Acre and there died."
Richard de Camville (of Warwick) confirmed as founder of Coombe [current spelling] Abbey, circa 1148-50. He had a wife, unnamed. His son and heir Gerard was old enough to witness charters, and Richard's brother Hugh was another witness. Source: Dugdale Monasticon V, Combe, Warwickshire, I, p. 584.
Cannot confirm the 1147 reference - there was a brief incursion by the teenage Henry of Anjou that year, but he had only a small force and was soon sent packing.
The Richard de Camville who went crusading with Richard I was CERTAINLY NOT the same person as the founder of Coombe Abbey *or* the second husband of Melisende de Rethel. He was a double orphan circa 1176, Melisende having died before 1171 (charter of Jumieges, 1170/71, made by the senior Richard "for the souls of my wife Adelice and second wife Millicent" (the younger Richard subscribed but did not witness the charter), and the senior Richard falling sick and dying in Apulia as a member of the entourage to deliver Henry II's daughter Joan to her promised husband, William II of Sicily [1176].
What Henry II did next shows that the younger Richard was considered not yet to be of age - he grabbed the manor of Stanton and placed it in the custody of Richard Rufus. It took young Richard until 1190 and the favor of the next King (Richard I) to bring Stanton back to the Camville family. But they didn't keep it, because young Richard went off on the third Crusade and never came back. As of 1192/93 the holder ("jure uxoris") was Robert Harcourt, and the manor remained in Harcourt hands and eventually became known as Stanton Harcourt.