Question 1: What type of conduct is expected of a Vaishnava? How should the conduct of a Vaishnava be any different from others?
Answer by Romapada Swami: Lord Caitanya, when asked this same question, replied “asat-sanga tyaga ei vaishnava acara”. This means that a Vaishnava is not attached to impermanent things (asat); he is also likewise disinterested in grossly materialistic persons who are absorbed in impermanent pursuits. This does not mean a Vaishnava shuns people and things of this world. He deals with them from a position of knowledge of their proper relationship with the Lord, and therefore without personal attachment and without intimate dealings with worldly-minded individuals.
Externally a Vaishnava may conduct their life as any other honest and virtuous person. The only way their conduct is expected to be different from others is one of qualitative difference, i.e. in their steadfast cultivation of compassion, honesty, humility, equanimity, non-violence, simplicity, cleanliness etc. — consistently with an internal cultivation of doing all of this for the satisfaction of Krishna or Vishnu, as an offering of oneself and one’s life to Him.
A Vaishnava also chooses a lifestyle that reflects his/her faith and respect towards the Supreme Lord and His devotees – they are naturally attracted to chanting the Holy Names, respecting the Deities, observing the holy days, eating only sanctified food (Krishna prasadam), dressing simply etc – but how these principles manifests in their outward appearance and conduct depends on each individual devotee.
Question 2: What exactly are/should be the attributes of a Krishna conscious devotee? How can a devotee be identified, by his behavior, actions, or intents, or all of them?
Answer by Romapada Swami: Lord Krishna discusses this particular question at length in many places in the Bhagavad-gita — Ch 2 Verses 54-70 and Ch 12 Verses 13-20 in particular. The intent of another person is very difficult to discern, especially within short period of time, but a devotee can be identified by how they speak, how they act, and particularly by how they respond to trying situations such as success/failure, honor/insult etc, and how they choose to act in their leisure. Note that these are the 4 questions asked by Arjuna (BG 2.54).
Ultimately, Krishna alone knows the heart of every individual, and it is not easy to judge who is a genuine devotee simply by external traits or circumstances alone. However, Krishna describes these symptoms to give us a guideline how to identify and appropriately serve persons at different levels of Krishna conscious development.