Hi kenjib, and thanks for the praise!
You'll be happy to know the following things about Broadsides:
1) The trade info/economics of seafaring is covered in an article we wrote for Gaming Frontiers #3. We've included prices for common goods, wages for hirelings (sailors and the like), depreciation of ship value, and costs for booking passage and having specific items shipped to new locations. We also included random encounter tables for the open seas...
2) We are having a cartographer design deck plans for all of the ships that appear in Broadsides. The plans will be available for download from the Living Imagination site in the next few weeks.
3) We are also going to be designing more ocean-borne monsters, also available for download from our website.
4) We are going to be supporting our own product! We have, on the drawing board, three or four books specifically designed for use with the Broadsides rules set. We intend to have new ships, new PrC's, new equipment, NPC's, encounter areas, port towns, and so on! We're not sure of a release schedule yet, but keep your eyes open.
In regards to your request for the mass combat/boarding action mention, we're not sure if we're ever going to do that. Plain and simply, we're not happy with any of the mass combat rules that currently exist, and designing a whole set of rules for that purpose may be beyond our scope. But, the future is uncertain... we shall see what happens in the next 3-6 months. Expect a lot of changes form LI as a company, and our products will reflect that.
Again, thanks for the praise!