Lots of chatter indeed.

First off, let's address the issue with
>my character is good at sneaking, why can't he sneak past guards?
RNG here determines whether or not the terrain is actually good for sneaking, and whether or not these guards are the mooks that you think they are. Think you're tough shit? Oh noes, the guard captain was amongst the mooks, and he knows something is up.

>my character is going to backstab someone and they have no idea I'm there, so I'll totally hit!
If the monster fails to detect you when you spring from the shadows, you will definitely hit it...though whether or not that hit will do damage is also a question. Scales and tough hide and armor is a thing, but so is completely different bone structures and organ placements. Or, you know, your stubby little kitchen knife just can't cut deeply to OHKO.

>my character is going to shoot a motherfucker in the face with a gun!
Firearms aren't perfect. There's always a chance of misfire. The reason people still use firearms is because these still pack a big ass punch. Also, a Gunner shouldn't really be in point-blank range of anything. Alternatively, there's something called aim dodging. You've seen those gun kata shenanigans? That's why there's people who actually go melee modu: a line is harder to dodge than a point.
[hr]
Now, here's the hammer.

This was never a realistic RP. The anime/manga tag should have clued that in. If this was realistic, everyone would be picking up long range weapons, specialize in sneaking around, and running off if they can't take down a big monster.

Modifiers do exist, and are what will give you the edge you need to add some degree of consistency to your rolls.

There are no low-leveled monsters. These monsters are things that HEROES are meant to slay. You are all just adventurers.

Wounds will actually matter. If you get stabbed in the arm, that arm isn't going to be usable. Shit like that.

In the spirit of the hunt, however, rolls that detail whether or not you hit will only be done in the heat of battle. So if you are sniping from a distance and are unseen, or if you are popping up behind them in an ambush, yah, that's an auto hit.

And if some people are REALLY against dice rolls, I'm willing to set it for those people so that you don't have to roll. Instead, it's assumed that you always roll half the value of the dice you're rolling, before adding your modifiers. Gives you the consistency you want, but also seals your ability to pull off some really amazing stunts via rolling the maximum value.

Basically, this is a good example of how shit may or may not be like.
[youtube]v=QsO2cOM5TeY[/youtube]
[youtube]v=YOKbmAPd7CU[/youtube]
[youtube]v=aM6XbXBZh2M[/youtube]
I'll probably set something up so that you progressively get shittier at doing things the more wounds you accumulate.