Maybe the missiles are supposed to be able to do more damage to larger targets, and the damage they are already doing to medium targets is intended and balanced? After all, they have excellent range and flexible choice of damage. Maybe the RLMLs are overpowered by offering cruiser missile paper DPS which translates too easily onto the target.

At this point I think CCP will be be better served actually creating an entirely new calculation of which to base missile damage application. Perhaps one based on mass? The more massive the target the more force absorbed (and therefore damage taken) by the target, max force determined by the missile fired (think leaf in the wind vs static structure). Add in a corresponding vector equation to determine damage bonus/reduction based on speed moving towards/away from the origin point. I imagine such an equation could be created to actually be less server intensive than the current given these values should already be readily available based on what is already pulled.

Because they're already pulling variable sig radius and trajectories. I don't need to see their code to know it's there. Activating a prop mode to increase mass is updated just like updating a sig that has been target pained/increased via MWD. One would argue you would actually have less possibilities of a collision due to the limited ways a mass can change in combat. Additionally your movement through space is calculated via vector equations as we are in a 3D space. Which again is readily available as that is how they would have to go about calculating transversal/orbits/basic location in space. There are other ways, but would require more calculations to be done on the back end, which is why I can say with almost certainty this is how it is being done.

In short, what I have suggested makes use of what is already available, there are no additional calculations needed to obtain these values over and above what is already being done in the current system. More so since the introduction of Brain-in-the-box.

The "intended role" of RLMLs is terrible and these changes are pretty great.

I read most of this thread but Suitonia really crushed it out of the park with this one. The grid really is a big issue because the reason you see so many Caracals being used is because they get great application and a really heavy tank compared with any other ship in the attack cruiser line and a lot of that has to do with the fact that a T2 rapid light launcher uses only 77 grid. The two with the next least grid usage among cruiser weapons are:

Dual 180mm Auctocannon II: 88 grid
Quad Light Beam Laser II: 89 grid

Consider that these other two low grid users frequently under perform and so are rarely used especially the quad laser and yet both will take more out of your fit than rapid lights. Consider increasing the grid usage on rapid lights to the 90 - 100 grid range please and this is completely irrespective of other changes (even focused medium pulse laser IIs take 125 grid). Sure, the ships that fit rapid lights tend to have less grid on average but not 40% less than average. How often do you see 180 autocannons or electron blasters being used without multiple reps or oversized ASBs? Ships fitting rapid lights sacrifice nothing in their fits because the fittings are so low on them. The point is that when fitting other weapon types to save on grid your downgraded weapons IS the sacrifice, for rapid lights this is not the case as they are the preferred weapon anyway.

On another note, I like that you are at least looking at HMLs but their problem isn't really their damage it's the very poor application they get against small fast ships, which let's be honest, is going to be a situation that comes up often in pvp. Part of the reason people lean to rapid lights in the first place is that unlike HMLs or HAMs damage application is a non-issue. In the case of kiting fits especially crash boosters are not really going to be an option for HMLs because rolling that speed penalty is a really big deal, so don't expect those fits to swap over to heavies with these proposed changes, they'll either stay rapid lights or change ships. Missiles are not like turrets where you can at least try to fly in a way that will drop transversal and allow you to land hits on small ships. I'd even accept a small nerf to the damage of HMLs if it meant they could get mediocre damage application to small fast ships.

Rapid rockets doesn't even make sense. It's like asking for a rapid torpedo launcher rapid ham launcher

Phoenix/Leviathan would like to have word with you about savior known as Rapid Torpedo Launcher