Well, as you might have seen before I discontinued that AAR, I found it worth it to create massive Civilian Ships, train them with no maintenance costs for two years, and then refit them to a military design with the new engines that are available by now.
Sure, it costs more then double the build time and many more resources, but you get Elite Ships at the pinnacle of your tech level.
Not sure that's possible anymore.
As for jump point pickets, it's probably a good idea to have a reaction force on an asteroid and a sensor ship on the other side, if something approaches, move picket force there.
Old ships are obviously a good choice as well.