For Resizing, it certainly doesn't create any balance issues, so I would probably just require a single spell mastery roll to tweak the spell intended for armor. Of course you could also create a new spell list for clothing, along the same lines as Shoe Enchantment. All Sizes is on that list as an 8th level spell.
It seems to me there are a number of unnecessarily complicated design constraints here. For example, if you provided a limited number of outfits you could use Multiform. If you don't need it to be a real physical change, there are various illusionary ways to change an outfit, and that also solves the fit problem. Putting the enchantment in a ring is more complicated than putting the enchantment in the outfit itself. Etc. So basically the general problem of having an outfit for every occasion is solvable in multiple ways, if you want to solve it in an extremely specific way that is different from all of them, maybe take one of those existing methods and use it as a general baseline for the item cost and level, and then use GM fiat and don't worry about the rest of the details.
Regarding pg 204 (table 6-1c) vs table 5-3c, they should give the same results. Using a level 1 essence effect as an example, the spells involved are Work Lesser Metals (5), Embed I (3), Constant III (17), and the spell to be embedded (1). Except... I think there is an error now that you mention it and they are actually calculated based on Work Mundane Wood (4). So the item level is 17, the total levels are 4+3+17+1 = 25, and the price is 17 sp materials + 2 sp labor = 19 sp per day for 25 days = 475 sp. So that Work spell might be throwing you off.
