1. I don't trust nylon or plastic cutting boards for meat or poultry. I don't feel like they can ever get clean enough without high temp or hard chemical sterilization. I've worked in commercial food places that use high temp automated washers and triple sink sanitizer setups, which will destroy wood but is perfectly right for the nylon boards. For home cleaning (hot tap water and dishsoap) a decent hardwood board washed well between meat/raw veg ingredients, or two seperate boards for the respecitve types of ingredients, that is perfectly fine for the typical home kitchen. The newer bamboo work equally well except I find they chew up my knife edges.
2. From personal experience, I can say there is no perfectly vegan diet. Most medium to large scale vegan staple farming requires some kind of invasive animal life control, whether it be natural control of plant eating pests or squishing hornworms and cutworms with your fingers. All life is life, and all life feeds on life.