A gnome can get Quickrazors without needing the prestige class or feat, by swapping his racial weapon proficiencies.
Casting Grease via Arcane Dilletante is a 1/day option, as you can't prep the same spell twice. Beyond that, items (wand) would need a higher than normal CL, as Grease only lasts round/level. Also, it's only a 10 ft square, I think you're severely overestimating how long it would take an enemy to get out of it. In any case, I loathe set up times and try to avoid them like the plague. I guess with cunning surge "set up time" turns into "3 inspiration points," though. I'd still rather just buy a ring of blinking, dip into Swordsage for flatfooted-granting maneuvers, grab some skill tricks, etc...
Cunning Surge will get you one extra attack. If you try to use CS multiple times on the same turn, the DM's just going to ban/nerf the class feature anyway.
Cunning Knowledge can help your Iaijutsu Focus check once per day. It will boost your damage by mid levels by 1d6-2d6 on a single attack.
I have never heard anyone claim that Factotums count as having wizard spellcasting and can thus use the spell items just because they can use spell-like abilities drawn from that spell list before. You cannot do this. However, with UMD as a class skill and every reason to want a good charisma score and circlet of persuasion (helps UMD, Iaijutsu, Intimidate, Diplomacy, and more!), you can probably use wands and scrolls just fine anyway.