I don't know what "no fly" netting is, so I can't help you there.
I have never seen my guineas attack my dogs. The girls will get out accidentally some times and chase the birds (We're still working on this with them), the guineas run and flee like the rest of the birds. The slowest bird gets caught. (Normally a rooster, even more normally a Cuckoo Maran rooster)
Now, the girls' mother(Prissy) doesn't always chase the birds. She used to chase them a little when we first got her, but now she only chases the guineas, and she generally only chases the guineas when they (Normally the hens) come real close to her and start "buck wheat"ing and/or calling alarm. (Prissy'll be laying down and the guineas come up and start making a fuss, then she chases them off.)
Rarely Prissy will chase the guineas when they're minding their own business. But I have never seen the guineas attack her. Now our foster-Chihuahua was intimidated by the chickens and guineas, so if you have small dogs you may want to look out for them.