An update on stats plus skills

I posted a modified version of the last post on an rpg design message board I've haunted for over two decades, and some of the feedback I got was even helpful. Though there was some discussion of differing tastes for the amount of randomness one allowed, the biggest concern seemed not allowing inherent talent or randomness overwhelm skills.

I think I'm fairly satisfied with the ratios I have now, but I'm probably going to add a non-proficient penalty to physical skills to limit the talented amateur effect and try and define which skills are impossible to attempt without training.

My current headache is the modified to-hit and damage roll.  I'm considering a series of skills/modifiers that allow characters to affect to-hit and damage separately without going back to multiple rolls. Unfortunately, it adds some complexity to evaluating the combined roll and it is proving difficult to find a simple and elegant solution.

Blowing the Dust Off an Old System

For the last couple of years, I've mostly turned to online MMO's (and DDO in particular) to scratch my RPG itch.  Lately I've been catching up on my favorite podcast Fear the Boot which has put me in the mood to do some old fashioned tabletop gaming, so I've decided to blow the dust off an old system I'd been working on.

I've been re-examining pretty much all my design decisions and one of the basic questions I'm considering is this:  given a system in which contests are resolved with a combination of stats + skills + gear + die roll of a range from 1-X, how much weight should each of those elements have? 

For example, in D&D 3.5, X=20, the BAB of a capped fighter = 20, and IIRC the max starting STR for a starting human (baring other effects) is +4 which is 20% of X and as for gear, something like a Holy Avenger sword would be +5 or 25% of X.  This gives us something like a skill + stat + gear total of 145% of the max value of the die.

Is that a good ratio?  Should the randomness be greater or less?  Should stats be more important?  Should gear be less?  And of course none of this takes into account temporary magic buffs which can add substantially more, or (at least in the case of D&D) feats and enhancements that may also add even more.

So whats the ideal ratio and why?