You have an interesting approach here.
If I understand correctly, the way that hitting with various items works is - to you - a hidden rule. The players only state that they want to hit the dragon with, say, a round-house kick. They have no idea about their chances.
Is D&D not an RPG then? I have a pretty good idea what rolls I need to make for my fighter to hit the dragon. There is hardly anything hidden. (Unless it's not really a dragon but an illusion or something.)
Players all begin the game at 1st level (no matter what RPG they play or how powerful their characters). They learn through play what their abilities are in different circumstances and what the distributive odds are for any action involving dice rolls. The chances as you say.
What traditional RPGs are, games with rules hidden behind a screen, falls under the definition of Roleplay Simulation. Specifically convergent RPS. Divergent RPS would be more akin to the storygame RPG design. These are sociological terms and relate to the kinds of roleplaying exercises folks in those circles perform. Convergent exercises are where one person knows the truth and the others are guessing at it, divergent exercises are where all participants have a hand in determining what is true.
As for a games not needing rules, it does not matter. Any game will have rules. The most common rules for free-form storytelling, for example, are about character ownership. (You cannot state what another player's character does or thinks.)
Actually, D&D has pretty much the same rule. You cannot say, what my character does.
Scene framing (stating what the scenery looks like) is another common topic. That is delegated mostly to the GM in D&D, but player's might still be expected to explain what their home town or their rooms look like. Other RPGs like Feng Shui or Wushu allow players to state the presence of various items.
I agree, rules are based on patterns of behavior. No matter how a group of authors who gather to write a novel for sale choose to work together their will be some agreements made as to how it will be done. These are rules, but I would be wary about calling the act a game. It sounds too much like the ludic fallacy about treating the following of laws and other agreements in our world as a game.
My meaning was not to state games did not need rules. I said storytelling does not need rules. Storytelling is actually the opposite of following rules as rules are predefined stories of their own right. Scripts to follow by people. Not following the script, the rules, means a person is not playing the game. Storytelling is the act of making scripts, not the following of them. Rules can be added to this endeavor, but they are not essential. That was the point I was attempting to convey at least.
Now in D&D (and most other RPGs), there are dice and numbers, of course. And succesful players will consciously invoke those numbers to achieve certain results.
"He is bloodied. I'll use my standard action to roll Intimidate, and make him surrender."
Few is hidden this situation. (The target's will defense... maybe.) But tactic there is. The player made the decision to spend a resource (the standard action) in order to try something (roll Intimidate).
Therefore, you can have tactic with near to no hidden information. There is no hidden information in chess after all.
IMHO what you are talking about are simulation games, not RPGs. All games are strategy games to some extent as they involve navigating the rules effectively. But in a traditional RPG these rules are hidden. The strategy not in navigating them, but determining them. In a storytelling RPG the rules relate to a game that has nothing to do with the story, but rather determines who gets to tell what part of a story.
A number of people believe any act included in other's creating of a story is also a storytelling act, and therefore roleplaying. For instance, the person who cast the dice I use, the person who created the paper for the RPG books, the cartographer who drew the map I borrowed of a town in Iowa. In this philosophy, all these people were engaged in roleplaying when they performed these acts as they helped craft the story our group is telling.
I don't fall into this current ideological trap of literary theory, one where everything experienced in the world should have the word "story" prefixed to it. It's a philosophical black hole. To my understanding, the game you are playing above is a simulation game. Perhaps it is added on to a storygame as in 4E? Or perhaps is it one of the dysfunctional designs? (I use that term here as I believe professional game designers refer to freeform games) By which I mean the kind where the rules are in front of the screen and a GM "just sort of makes up" whatever is not covered by the rules. Either way, attempting to play a simulation game as a RPG won't work. At best it only works as a narrative resolution mechanic incorporated within a larger storygame RPG.