Something that you might consider adding to your list:
After they updated potion tooltips to actively display the effects in real-time, I noticed that beers and ales were not included in the update.
While they are not commonly used in combat, many have other effects that can be quite helpful (e.g., Dwarven Stout's mining bonus or the poor man's magic potion, the Wizard's Mind Bomb), and I think that these positive effects (as well as the negative skill effects) should be represented in a tooltip.
I guess ales would work as food listed under consumables, since they heal a few hundred hp and would apply a buff afterwards (similar to higher levelled pies).Improvements: Tooltip / (F2P) QoL v2 Quick Fixes: Invention
I played a game recently (Jon Shafer's At the Gates) and it had the best tooltips I've ever seen in a game. I could only wish for something similar to that to be introduced, but considering how poor current tooltips are.. I highly doubt that would happen.
All of your suggested improvements would definitely be welcome. Information should definitely be relayed better to the player. Especially in a game as massive as RuneScape.