Like Corrina, my properties are different than yours, so what I use may not work for you. But I'm happy to make some suggestions
Whether or not you can co-wash really depends more on your hair properties, not your wave/curl pattern. Since you mention that your hair is high porosity, you're likely to lose moisture easily, so that will be important to consider when you're looking at products. Your allergy to shea butter stinks, as that is a main ingredient in a lot of moisture-rich products, but it's not impossible. Since your hair is course, you're probably right that you may be sensitive to protein. Some people do okay with certain types and not others, so you'll just have to be cautious and see how your hair reacts.
GVP conditioning balm found at Sally's (knock-off of biolage conditioning balm) is very moisturzing, and does not contain shea butter or protein (I think the Biolage version has hydrolyzed keratin, but lower down on the ingredient list). A lot of people use this as a RO or DT. You can also take a cheap condish that you know doesn't react badly with your hair, and just add oil to it for added moisture (I like to add olive oil and coconut oil to Tresemme Naturals conditioner for my DT - this is another protein free conditioner that provides decent moisture and slip). You may also want to think about sealing to lock in moisture - some popular oils are grapeseed, sweet almond, apricot kernal, coconut, or olive oil. If you don't already, you might want to think about a leave-in conditioner too.
As far as styling products, a lot of wavies/curlies like either a firm hold gel or gelly product. Some examples are KC Curling Custard and Biosilk Rock Hard Gelee. These will help hold your wave/curl pattern and reduce frizz (the KCCC is protein free, but I believe the BRHG has silk protein - neither contain any shea butter). Some people also like to use mousse - a popular one is Sauve captivating curls (I believe this contains dimethicone). Others like more of a serum type product - Tigi Control Freak is supposed to be great at fighting frizz and provides some soft hold (I believe it has a water-soluble cone).
One other thing to consider when it comes to frizz, is technique. My hair responds better when I apply my products to very wet hair, not just damp, and when I plop and then air dry without touching it.
Hopefully some of those suggestions help - I know there is a lot out there to try, so just be patient - and good luck!
2c/3a, botticelli/wavy/'swavy (huh?)
fine, dense, normal porosity/elasticity, dry climate
My favorite brands are Kinky Curly, As I am, Curly Kinks, Curl Junkie, and Darcy's Botanicals. Also love sealing with oils (loving argan oil right now) and styling with jelly products (KCCC is my current favorite). Mostly trying to keep it simple!
CG since 12/29/2011