1. ID Create/Escape (Both trained at the same time)
ID Escape allows him to get away from instances. The higher level, the better he can run away from enemies even higher level than him. ID Create gives him the slow time instance allowing him to train better.
2. Bind:
The ability to run away and fight another day.
3. Observe:
If he observed all the high lvl people hes run into. Chunbunmoon Elder, Dark Summoner, Manager of Abyss Auction, The Witch etc... He could better strategize how he wants to level up his stats and skill. I think someone said it perfectly, Info is King.
4. Summon Elemental:
Its utilitarian. rock shield, rock hand thats kinda like a CC... and it makes for a decent offensive ability to help kill mobs to level up.
5. Physical Endurance plus Yunhon Soul Recovery:
I know its cheap to combine these 2, but it makes sense to me. Let a zombie naw on you... Level up physical endurance.... then heal yourself. Anyways, physical endurance is my 5th pick because it will help if he is up against multiple enemies. He can ignore the physical lower level fooder and CC the caster to escape.
6. Other Skills (Outside original topic paramaters)
He should put lots of energy into obtaining many skills. Lockpick would be great using shapped mana cause if he gets caught and shackled he can escape.... even if he never trained it before, and was lvl 0, as long as he had it he could lvl it up during captivity.
Process of elimination
Not Chunbun Outer Ki Technique Good because of the Vitality and stamina recovery rates, but its passive only so harder to grind. (How would you lvl it up anyways)
Not Chunbun Spirit Technique.... 100% of 6 stat points is only 6 stat points. Better to buy armor from Abyss AH. If he evenly distributed his stat points then I would re-consider this.
Not Life Drain: Good for sustained farming, but without lots of vitality, 1 hit he is dead anyways.
Not Mana Shield: Although a great skill, and could take some hits expecially with higher mana regen rate, but it doesn't help him escape.
Not Chunbun Foot Techinque Although great for running away he is currently to slow for the % increase to make enough difference in surviving an encounter.
This leaves:
Physical Endurance and Summon Elemental and spinning mana arrow