Thanks for your questions. Eremitical life is, paradoxically, both constrained and incredibly free. In the Roman Catholic Church we now have canon 603 that defines eremitical life and allows for consecrated solitary eremitical life which includes not just solitary hermits, but solitary hermits who come together in colonies or lauras which do not rise to the level of juridical congregations or communities. (Some country's bishops, Spain for instance, have created guidelines for such lauras focusing on the limits these should observe.) Canon 603 has several conditions or central elements that are part of the essential definition of the solitary eremitical life, namely, the hermit lives a life of assiduous prayer and penance, the silence of solitude, and stricter separation from the world, within the framework of the profession of the Evangelical counsels; they do this for the praise of God, and the salvation of others, all under the supervision of the diocesan bishop and according to a Rule of Life the hermit writes for herself. Whatever else one does (limited ministry, etc.), one must live these elements if one is to truly be a hermit.
Canon 603 thus also implicitly refers to other canons having to do with the Evangelical Counsels and also with contemplative life in the Church. Thus, dioceses can require things c 603 never mentions explicitly as part of the profession and consecration of a c 603 hermit, and even when additional canons don't apply directly, there are encyclicals and exhortations that do. So, for instance, a diocese wishing to profess a diocesan hermit may refer any suitable candidate to texts like The Art of Seeking the Face of God, Guidelines for the Formation of Women Contemplatives, Vita Consecrata (Consercrated Life), The Gift of Fidelity the Joy of Perseverance, New Wine in New Wineskins, and of course, Ponam in Deserto Viam (The Hermit's Way of Life in the Local Church), et al. Hermit candidates and their spiritual directors should be familiar with these writings. Of course, these do not simply provide a list of naked standards as though one size fits all. They provide reflections on a vision of consecrated life that an individual should take on (and be helped to take on) in a way which illumines her life and makes it a gift to the Church and larger world as well.As noted above, to try to embrace such a vision in response to God's call is both constraining and incredibly freeing. The life one is called to is both regular or ordered in particular ways and also free to respond to more individual or particular gifts. Both dimensions are of the Holy Spirit and both must be honored if one is to live one's vocation faithfully and with integrity. Some of this may surprise people when they are reflecting on eremitical life. For instance, this life is meant to be lived for the sake of the salvation of others. This is an integral requirement of what it means to be a hermit, especially with an ecclesial vocation. It is not just that the hermit prays for others, though this is certainly a dominant note in every hermit life, but also, that the hermit may be involved in limited ministry to others so long as such ministry enhances rather than detracts from her eremitical life.
How does one discern this? Well, not according to an abstract list of standards; rather, one looks to the quality of the whole life one is living. Does this form of limited ministry lead the person to a stronger prayer life, a greater sense of her call and dependence on God, a life defined more completely in terms of the Word of God and as imago Christi? Does it allow for "the silence of solitude" to become not just about the absence of noise in some form of isolation from others, but also the stillness of human wholeness and holiness in communion with others? If it does these things, then discernment affirms that this is likely to be something God is calling one to. In the past I have spoken about this in terms of the ministry calling me not only out to the world around me, but back again and again to the solitude and silence of the hermitage; the limited ministry of the hermit is one legitimate way the life of the hermitage overflows in mission, rather like the image from last Sunday's Gospel: [[Give, and gifts will be given to you; a good measure, packed together, shaken down, and overflowing, will be poured into your lap.]]Hermits learn over time to honor the various ways the Holy Spirit calls us to serve the Church (both as the Body of Christ and so, as a communion of brothers and sisters in Christ). They are also helped in this by their spiritual directors, delegates, and (though usually less frequently or regularly) by their bishops and pastors or confessors. Those exercising the ministry of authority in our lives generally do so out of love and those who are really good at their jobs have a very clear sense of the ways the hermit needs to grow and change. Thus, a list of standards is only minimally helpful because it neither knows the person or the way the Holy Spirit is working in her life. What is necessary is faithful and prayerful dialogue with someone knows us well and who lives and knows what it means to live a contemplative life of prayer consecrated by God for the sake of one's own call to holiness and for others as well. To gauge the quality of an eremitical life according to a list of requirements, it seems to me, is to miss the point.
A hermit is not merely someone who lives alone in silence while saying prayers at various parts of the day. Any misanthrope could do that! S/he is someone who, in the silence of solitude, lives with and in dialogue with God, and who, in light of this intmate relationship is capable of loving not only God and herself, but others as well. The Camaldolese congregation I am affiliated with apart from c 603 speaks about this kind of life as one of The Privilege of Love. It seems to me that this is the single or overarching standard by which a life lived under c 603's requirements is really to be measured. Of course, all of the central elements I listed above are definitive of this form of life, but within one's faithfulness to these, one must ask, is the person growing as one who loves God, themselves, and is committed to the growth in holiness and wholeness of others as well? Is she responding to the Holy Spirit even if this means doing something other hermits are not doing? Do those exercising the ministry of authority in her life agree with this sense of things? If so, then she is living c 603 and the life it describes faithfully!I sincerely hope this is helpful. I have tried to give you a sense of the codified requirements that bind diocesan hermits and I have tried to indicate why no single list of "standards"--- especially if applied from outside a lived eremitical life --- simply won't work. C 603 is a place to begin. Ponam (cf above) is important as well if one wants to see how the Church views this vocation. Your concern with "doing all the right things" is very much a beginner's concern. There is certainly nothing wrong with that! If you are truly called to an eremitical life and embrace that call, you will eventually come to a place where your deepest concern is to be yourself in response to God's invitation to life in Him. Similarly, your concern that God calls hermits to different incarnations of the eremitical vocation won't bother you so much as it does currently. You will recognize the deeper dimensions of things like silence or solitude and let go of worry about any more rigid, less essential, and more superficial senses of these defining elements.