First, your spelling needs work.
Second, you're describing a completely different game.
"Adventure Rank" was in 1.0. They dropped it because it was difficult to manage and ended up not really meaning much.
"Weapon Skill Levels" existed in other games, but those games are built completely different from FFXIV. What you're basically describing is a more complicated version of FFXI's system.
I'm sorry but your suggestion is nigh incomprehensible and describes things that really have no place in this game's system.
It's not "wrong" either, it's a different approach. The developers have taken the path they chose because it allows for the most versatility for adding content later.
I cannot emphasize how important it is for an MMO's systems to be simple to explain.
Let's use an example: Your explanation is nearly 2 paragraphs just describing how leveling would work.
How it CURRENTLY works: There are 9 classes in the game. When one job reaches 30 and a specific one is 15, you unlock the Job. The level cap is 50. You can switch to other jobs whenever you switch weapons.
Simple, straightforward.