Concentration and Craft? Hm. Maybe make a sliding scale for Concentration, so you don't have to make a DC 60 Concentration check to cast your spell when the enemy barbarian power attacks you.
I'd be thinking of stuff like producing (limited) magical items (ie - non magical bonuses to hit and damage applied to weapons, additional levels of masterworking), producing standard equipment in under a round, and that sort of thing.
Decipher Script . . . I think we just need to use language rules that are adapted out of d20 Modern or Call of Cthulhu. It's not really an epic thing.
You could always let it do stuff like work out the true name of creatures from their possessions.
Diplomacy - Hell, DC 35 is enough to make an enemy friendly if you have a few minutes. DC 45 can do it as a full-round action. That's as good as a charm person. Similar DCs for compulsions and suggestions.
Yeah, diplomacy is probably all good already. Although maybe DC increases for diploming things that don't normally communicate? Like -20 to diplome an ooze or something? I dunno.
Disable Device - I'm not familiar with what epic stuff already exists for this one.
Mostly stuff to let you do it quicker. I'd say +5 as a single round, +10 as a move equivalent and +20 as a free action. The original DC's start at +20 and end up at +100 (??)
Escape Artist - If handcuffs (manacles) are DC 30, then I've seen people who must be 10th level. Maybe make wriggling through a wall DC 40, and a wall of force would be DC 50.
I'd probably NOT have "wriggle through a wall". The epic book has "wriggle through a space less than 2' across" at 80, and "wriggle through a wall of force" at 120. I'd drop those down to 40 and 50, with a halving of the 2' for every 2 points above 40.
Forge documents you've never seen? Create items which fool magical divinations?
Gather Information - DC 40 to read minds? DC 50 to see the future?
The epic book has -20 to avoid suspicion. I'd change this to "if you beat the DC by 10, you avoid suspicion".
I'd also have +3 to halve the time taken. Which means for an average gather information (dc 15), a 40 would get you 8 halvings, bringing you down to between 30 seconds and 2 minutes. Basically your character just turns around and says "hey buddy, you got a treasure map for that place, right?" and voila, they do.
Handle Animal - Train an animal in a round, DC 40. Train a magical beast in a round, DC 45.
Heal - This skill ought to give back hit points. Maybe DC 50 lets you bring someone back from the dead.
The epic heal skill sets a DC 50 to give a nights rest in an hour (but only 1nce per day per patient)
DC 100 gives you a weeks worth of the same.
So - DC 50 gives us a weeks worth of healing in a single hour.
Now, to get any kind of smooth function, we probably want to have heal 'time squish' rest times, starting at DC 15 (where it still takes a whole night) and scaling to DC 50, where a week's worth of total rest only takes an hour.
So how about if we halve healing time for every +5 beyond 15? That works out about right.
Hide - Invisibility gives you a +40 bonus to Hide checks. Thus DC 50 means you're effectively invisible anyway. Opposed skills like these are actually pretty balanced as is.
EXCEPT that blindsight, blindsense and tremorsense just flat-out defeat them, full stop, no questions asked.
Of course that just means that hide should have a reduced effectiveness versus those. Say -10 versus blindsense and -20 versus blindsight?
Intimidate - Should be able to cause fear effects. Or maybe intimidate should be compulsions, while diplomacy handles charms?
Well, for a start -10 to intimidate as a move action, -20 as a free action and intimidate applies to ALL foes that you threaten and that can perceive you.
Every point by which you beat their opposed roll gives an extra round of the 'shaken' condition.
Once you beat it by 5 points, frightened for a single round AS WELL as shaken for 5 rounds after that. Again each point is another round of frightened.
Once you beat it by 10 points, panicked for a round, frightened for 5 rounds after that, shaken for 5 rounds after that. Add another round for each point.
Which means that (on average - all d20's are coming up as 10) mister +32 intimidate can throw in some flourishes to his fighting (for a -10, total of 32), and creatures with 20 hit dice (and no wisdom bonus) get shaken for a couple of rounds, creatures with only 15 hit dice get frightened for a couple of rounds and shaken for 5 after that, and creatures with only 10 hit dice are just plain out of the fight.
If the guy goes all out, and basically spends his turn fighting intimidating instead, he's frightening opponents with 20 hit dice for a little bit.
Maybe this is a bit much - we could drop it down by a little bit, or make the frightened and panicked statuses more difficult to achieve. Say +10 DC instead?
More later.
Oh, and use rope is a dumb skill.