Dress
Sankirtan is the way to the goal of prema, wherein Sri Nama recedes to the background and lila seva comes to the foreground. In prema, the lila within the name comes forth and takes precedent as one becomes a player in the eternal drama of Krishna lila.
Our goal is to serve Krishna in the form of sakhya or madhurya rasa, but in the nitya lila separation is not prominent, because Krishna does not appear to depart for Mathura and Dvaraka, as he does in the prakata lila for such a long time. So service in separation is more related to the way than it is the goal.
As far as what to wear, householders can dress in sattvic clothing. Someone more focused on the goal can dress as a member of Gaura-lila, in meditation on that lila, and with the aspiration to enter it in dasya bhakti for Mahaprabhu. Monastics should wear traditional monastic attire. But if outreach is hindered by any particular dress, those engaged in such outreach can adjust accordingly.
However, it is not a foregone conclusion that the traditional dress of Gaura-lila hinders outreach. It seems to me that people who would be alienated by thinking they had to change their dress to be a member would be even more alienated by thinking that they had to chant and dance in public to be a member, if not more so. Fortunately, the teaching is that they do not have to do either. One can dress in the sattva guna and practice in one’s home, and many Gaudiya Vasinavas do this today. Still they will in time be meditating on empowered descriptions of specific lilas coming from our founding acaryas, the Six Goswamis, that describe modes of dress, etc.
The fact that monastic dress in public for actual monastics is not an impediment to sharing the teaching is evidenced by the recent visit of the Pope to the US. Millions of people came to see and hear him, dressed as he was in flowing robes, etc.
An example of changing one’s dress in consideration of outreach is the sannyasa dress implemented in the line of Bhaktisiddhanta Saraswati Thakura. Traditionally the Gaudiya renunciates wore white and a short cloth. Hari-bhakti-vilasa cites sastra stating that white cloth is for Vaisnavas. Gaudiya tyagis like Sanatana Goswami wore short white vesa just above the knees, but not new cloth, rather only cloth previously used by others, and Mahaprabhu was pleased to note this. However, Saraswati Thakura experienced that babas dressed like this in his time were not respected by the public, whereas those from other lineages dressed in saffron were respected. So he instituted a renounced order of sannyasa and dressed his sannyasins in saffron with much success in terms of attracting educated people.
As a member of that sannyasa order living in the West, I find that this dress has some power. Many people go out of their way to smile, nod, and in other ways acknowledge that I am a monk of an Eastern tradition and indicate that they think this is an admirable lifestyle.
Every culture has a uniform for its religious priests, and it’s renunciates are to avoid the vanity involved in attire. Thus, they adopt anything from ashes to a simple cloth and make it a point to stand out in society.
Adopting traditional religious Indian dress in the context of worship and temple life is not the same as inappropriately behaving like one is part of Krishna-lila, although it is like behaving as if one is part of the extension of Gaura-lila in the present. This constitutes following the example of members of Krishna-lila in terms of their example in their perfected Gaura-lila sadhaka dehas. That is recommended.
There are descriptions in our sastras of Sriman Mahaprabhu dressing in his householder life like this, in white dhoti folded thrice. Very nice!
There are of course many descriptions of how Krishna dresses and the Deity is Krishna.
Diet
If you like someone, you cook what they like to eat. It is hard to argue against that. Yes, Krishna eats bhakti. But is the vegetarian diet of Gaudiya Vaisnavas based primarily upon ethical concerns or is it based upon what Krishna eats? It seems it would be both but with an emphasis on the latter. After all, one can make an ethical case for eating the meat of animals that have died naturally. In the beginning one should perhaps offer what one likes the most because arguably such an offering can be most lovingly offered. If you love something, you want to offer it to the one you love. But as you learn what he or she loves, you will want to offer those items.
Culture
Is Krishna-lila devoid of Indian cultural sensibilities? Descriptions of those lilas are passed on to us by empowered devotees. Without these descriptions, how will we meditate on Krishna, his form, his qualities and his lila? They may be limited in as much as language and thought are insufficient to express the nature of transcendence, but they are empowered descriptions that have the power to draw one into Krishna-lila.
Earth is one planet. Krishna himself appeared on Earth in one place. That place has a culture. Dislike for that culture on the part of one who identifies philosophically and theologically with Hinduism confounds me. We live in a multicultural world and different religious expression have arisen in different cultures. These cultures tend to correspond with the ideals of those religions.
As far as taking birth in the lila goes, you will take birth in the lila setting you meditate on that arises from immersion in Krishna nama. His form, qualities, and lilas arise out of his name, and those who have experienced this have related within the limits of language their experience of his form, qualities, and pastimes, and these descriptions serve to guide practitioners in raga bhakti.