Resist difficulty has been kind of a mystery to me. It is there but I haven't done enough resistant items (and always of varying %) to guess how big of a factor it is. I believe it was stated to be minimal for enchanting but it seems to be a minor to middling factor for ensorcelling which always seemed to draw from the same attributes in other areas.
T5 on 5x DCP armor
Level: 70
Sorcerer spell ranks: 110
Intuition (INT): 92 (26) ... 132 (46)
Wisdom (WIS): 90 (25) ... 130 (45)
EMC Ranks: 72
SMC Ranks: 72
Arcane Symbols Ranks: 72
Magic Item Use Ranks: 72
Difficulty: this ensorcellment will be difficult, but possible (5)
Attempt: decent attempt
Success!
T3 on 6x HCP armor
Level: 72
Sorcerer spell ranks: 111
Intuition (INT): 91 (25) ... 130 (45)
Wisdom (WIS): 91 (20) ... 130 (40)
EMC Ranks: 73
SMC Ranks: 73
Arcane Symbols Ranks: 73
Magic Item Use Ranks: 73
Difficulty: this ensorcellment will be difficult, but possible (5)
Attempt: good attempt
Success!
T4 on 6x HCP armor
Level: 75
Sorcerer spell ranks: 117
Intuition (INT): 93 (26) ... 132 (46)
Wisdom (WIS): 96 (28) ... 136 (48)
EMC Ranks: 76
SMC Ranks: 76
Arcane Symbols Ranks: 76
Magic Item Use Ranks: 76
Difficulty: this ensorcellment will be nearly impossible (7)
Attempt: excellent attempt
Success!
Success Factors
Primary
Level: ???
Sorcerer Spell Ranks: +2 per rank up to level, +1 per rank above level (uncapped)
Wisdom: +1 per stat bonus
Intuition +1 per stat bonus
Secondary:
Elemental Mana Control: +1 per 4 ranks
Spiritual Mana Control: +1 per 4 ranks
Arcane Symbols: +1 per 10 ranks
Magic Item Use: +1 per 10 ranks
Note: truncate, eg. 79 AS ranks = trunc(79/10) = +7 bonus)
Other
Magical workshop: +20 bonus
Mark