Before blaming Beowulf on a high success rate just because he uses maximum range weapons, you should know that his die rolls are exceedingly above average. As a long time opponent, I've been victimized quite a bit due to his die rolls. Also, the arcs of his weapons should be considered: all but one. He uses the classic FX and RX type weapons that our historical warships have used at their pinnacle of advancement which means nearly every turn every weapon fires at their enemy. I have often tried to use mostly front arc weapons (like in Star Fleet Battles), and lose due to those arc differences once the game gets to be a turning match.
I often use 30 range weapons as well, and not have near the success rate.
I think part of the uproar against range>18 weapons is that people are using the badly-designed book ships and think that's how ships should be designed, especially concerning the low ranges that those ships' weapons have. Most don't even have weapons that go out to 18. They're matched against each other (bad vs bad ), but once home designed ships show up they are easily overcome and not just due to range but also arcs of fire can play a role. I have a few designs that could beat a large fleet of those book ships with just a handful of my designs (being faster with longer-ranged weapons means I'll never get hit).
As far as figuring the cost, yes, I do believe range does not equal speed. It might be close, close enough that it's hard to really know the difference. Maybe that's why this is an issue, range-30 weapons are an extreme case that show that the equation is wrong. Perhaps the only way to really tell is to playtest extreme cases of both, where the cost is even for range and speed (is a very fast short-ranged-weapon ship equal to a slow long-ranged-weapon ship?).
By the way, range-1 and range-2 weapons INCREASE the ORAT over range-3 weapons. That tells me that the equation does have an issue with range.