You don't need netting. You may get some taken by mice (I know they like peas) so you may want to plant a few extra just in case as replacements.
Main problem with broad beans is black fly on the new growth in early summer - you can spray but good organic tip is to nip off the top soft growth once the beans have set (its this soft growth that attracts the flys). Also autumn planted beans are less susceptible as they are growing earlier in the season.
You might want to have some sort of fleece/cloche to protect them from frosts depending on how sheltered your plot is
