Is there a way to alter the probability of a warplane being created when using the random scenario? Personally, I don't like the warplane idea at all, so what I want to do is create warplanes for all planets in range, and then I can just hide them in the system map, 'faking' the idea that a ship can warp to any planet in range.
Sadly no. The closest you can get is to set all the planets to be a neighbor of one planet. Then all those planets will link directly to that one planet with warp lanes shorter than 15AU.
