Skills/Perks

I got the idea of adding a perk system into your games.  Using the SAO leveling system (idk if you want perks in SAO, since they weren't mentioned in the anime, but that's the leveling system I have the most info on), with a max of 500 levels, maybe every 10 you get a perk choice.  These perks could be pretty basic or more complex.  Some perks may have a prerequisite of other perks or of certain strength/agility values, like weapons.  I'll put a couple examples of what exactly I'm thinking below.

Low Level:
Iron Fortress: When defending (using a shield to block attacks), it becomes impossible for your avatar to be launched by a powerful attack (prerequisite: shield skill x(I have no clue about how high I should make the skill))
Throwing Apprentice (could be expanded at higher levels):  improves the accuracy and range of sword skills that involve throwing a weapon

Mid Level:
Wall Runner:  Vastly improves the traction that shoes have on any vertical object, allowing for limited vertical/horizontal wall running (prerequisite: Agility 400) (could expand into High Level that increases the traction even more, allowing Naruto style wall-runs)
Like a Feather:  Nullifies all falling damage (prerequisite: Agility 550)

High Level:
Unstoppable:  Multiplies max lifting capacity/stopping power by a factor of three (prerequisite: Strength 1000) (I'm thinking, this plus the strength modifier would allow the player to perform feats like catching the punch of a boss-level monster with their hands)
Jack of All Trades--Ultimate:  In terms of equipping weapons, the players strength and agility are seen as 500 points higher than it actually is (this would allow a player to equip weapons that would usually be outside their character build) (prerequisite: all previous Jack of All Trade skills)

These are, of course, only examples.  The actual perks could be anything.  What do you guys think?

Your proposition seems intriguing. However, there are some vague things that I would like clarified, such as the terms low-level, mid-level, and high-level. I am not an idiot and therefore know their basic definitions, I would just like to know how it would relate to the games. Do you mean higher the difficulty of obtaining, higher the level you have to be, or higher the skill you must have? This would be very beneficial.

I meant like player level (low level I was assuming character level 10-20, mid 250, and high 500 (max level)) That was also where I was getting the prerequisite numbers from. they said that SAO would have 3 skill points per level (1500 max) and I was guessing where a player would spend them, and how focused they should be for the skill/perk displayed

Ah. Thank you kind sir. I like your idea, so you may assume I shall support you one hundred percent on this issue.

Well that system wouldn't be right for sao, since we are going as accurate as possible with as we can

How many different kind of skills will it be, will it be like in the anime where it's a skill for basiclly everything you do?