Skill checks all require rolling equal or lower than the skill on d6. A skill of 6 fails on a roll of 12 on 2d6. The skills will all default to one, except as indicated. Thieves will get four points at first level and two at each level thereafter to improve them. Other characters just get on one point at creation to increase a skill as their “background.” The final skill list will be:
- Climb (climbing sheer surfaces)
- Hear noise. Elves & Halflings start at 2.
- Read Languages.
- Search (find secret doors, hidden items, etc., but not traps as this involves touching things) Elves & Dwarves start at 2.
- Sleight of Hand (pick pockets, palm objects, etc.)
- Stealth
- Survival (includes tracking, identifying natural poisons, and added to foraging checks)
- Tinkering (pick locks, disarm traps, and other mechanical operations)
- Traps (find or set traps). Dwarfs start at 2.
Note that a D&D Thief could put three points on Climb and one on Back Stab (below) to begin with skills comparable to a 1st level Thief in B/X D&D or LL. Advancement remains pretty close to the percentage charts, at least at low levels. So Raggi pretty much hit the nail the head on the head with 4/+2 per level idea.
Other abilities:
Back Stab: Any character with surprise or who is attacking an unaware foe gets +2 to hit. Characters with points on Back Stab (allocated from among skill points) increase this to +4, and also add a damage multiplier for each skill point (so a Back Stab of 1 deals double damage, two deals triple damage, etc.)
Underground orientation: Dwarves can detect new construction and determine their depth underground, as well as notice slopes and grades in underground passages. This requires a round or more of careful observation but usually automatically succeeds. The DM may require a Search roll if the grade is very subtle, the new construction is deliberately hidden, etc.
Vanish: Halflings can disappear (being effectively invisible) by just standing completely still in even the slightest cover. Outdoors they have a 5 in 6 chance of remaining hidden; indoors a 4 in 6 chance. This ability is not a skill and can’t be improved.
Swords & Dorkery 
You know, Mike, I think you’re having more fun building your house of cards than you will living in it.
Not bad. I’d be inclined to give everyone a point at every level though and maybe Rangers and Fighters if you use them, 2.
with thieves getting just 2 per level, even with their low XP requirements, I think that would encroach too much on their turf. Maybe a point every other level or something. I do envision certain quests or trainers offering bonus points once in a while though — train at the Assassin’s guild to get a point on Sneak Attack, spend a certain amount of time surviving in the desert or woods to gain a point of Survival, an Illusionist gives training in Sleight of Hand, etc.
Rangers would probably get a point on survival and stealth at first level and every third or so (I’d have to look at their normal progression and kludge it).
I was tempted to suggest “builds” (Put your M-U’s point on Sleight of Hand to be an illusionist, max out your thief on Sneak Attack at first level to be an Assassin, etc) but then I thought let the players figure it out.