I need to speak to the boss, but I think she is having really good results with something like "Back To Black" on the Fiat standard hood material.
During the winter I think she wipes the interior hood and boot fabric with a "Milton" mixture to clean out and prevent that mold/mildew growth.
To seal the fabric / zips we/she use Aquaseal products.
Hood care seems to be a mixed bag of recommendations and experiences. All I would say is that one should try to stick to natural fibre solutions. These should not damage materials. Another natural point is that most natural solutions require periodic renewal applications. This to me means that they are a) not too agressive b) not too artificial when comapred to the fabrics they are trying to protect.
Careful combinations, separated by time, of a selected few products, and monitored by a paranoid mind, can "hit the spot" for you. Sadly only you can try and achieve that "spot".