I think everyone would benefit from reading NAM Rodger's book, COMMAND OF THE OCEAN. Rodger thoroughly discusses British, Dutch, Spanish and French warship construction and the need to have supplies of seasoned wood (which takes a number of years to be ready) for proper construction. Rodger is far from critical of non-British ship design (except he does not like French design and for good reason) but he points out the problems. He states (and I have no reason to disbelieve him) that the ships the RN admired most were not French, but Spanish as they were more strongly constructed for a navy that had a large overseas empire to police and therefore had large holds for provisions (but a slower speed). I should add that the largest warship in the world in 1805, the Spanish SANTISSIMA TRINIDAD, was constructed in North America at Havana (as were many of the largest Spanish warships) of PROPERLY SEASONED North American wood.
Furthermore, far from obtaining wood from North America for warship construction, Britain throughout the period continued to get most of its wood from the traditional source, the Scandinavian nations and Russia from 1793 to 1815.
As for the 10-year life span of a ship of the line, I think VICTORY, which had an active service life of over 60 years, and many of her sister ships, would contradict that statement.
As for French naval training, exercising in the sheltered waters of Toulon in the fairly calm Mediterranean is a far different thing from sailing, manoevering and fighting a sailing warship fleet in the stormy and dangerous waters of the western Channel. In 1805-1815, only the RN was capable of that.
Again, I urge the readers of this Forum to read NAM Rodger, the bibliography alone is worth the price of admission.
DG