Protein needs are a spectrum more than simply craving or sensitive. It's called protein /moisture balance for a reason. Coarse hair typically has more than enough protein so it usually craves moisture. However that doesn't mean it never needs protein, and even when it's needing a bit of protein, it may only respond well to certain types. Fine hair typically needs protein for strength. However that doesn't mean it never needs moisture. Medium hair is in the middle as far as protein needs and requires moisture in balance with the protein.

Porous hair generally (but not always) has been damaged from heat or dye or brushing and needs protein to fill in damaged areas. Low porosity hair has problems accepting moisture, so protein can be problematic if you don't tailor application technique to suit the low porosity hair (apply to warm, damp hair, and perhaps assist absorption with gentle heat). Medium porosity hair accepts and retains moisture well, so again, it needs a balance of moisture and protein. As an example, my hair is fine but not high porosity and I use protein on wash days. Protein is always in my cowash, in my ro and/or li depending on the dewpoints, and I still need a pt every couple of weeks.

If you're sure your hair is both fine and highly porous, you should be able to tolerate a good amount of protein. Because you're highly porous, you'll need to balance that protein with some moisture, because high porosity hair can dry out quickly (holes in the cuticle mean it doesn't retain moisture well). You'll need to experiment with how much and how often though.

These links should be helpful:
Protein vs Moisture Pittsburgh Curly

Somewhat technical but worth reading:
Science-y Hair Blog: More About Protein
CG since 11/2011
2c /3a F /Mii, low porosity

Fall Products /Routine:
Clarifying: Herbal Essences Tealightfully Clean
Low Poo: Renpure Luxurious Argan Oil
CO: Suave Naturals Tropical Coconut or Daily Clarifying, V05 Strawberry or Kiwi Lime
Tresemme Perfectly (un)Done, Cure Care, V05 Kiwi Lime Squeeze, V05 Strawberry, Renpure Brazilian Keratin (old formula),
PT: IAGirl's as needed