I’m aware that the Baha’i are fond of the (Sufi?) mystic Rumi…
How do Baha’i pursue myspractices?ght/union with the Divine, and how does this compare/contrast with Christian or Islamic practices?
To what degree do Baha’i incorporate or borrow from Buddhist or Hindu meditative traditions?
Of the books revealed by Baha’u’llah that relate more to mysticism that are translated into English I would suggest that the Seven Valleys and the Four Valleys are probably the more "mystical’. These were composed while Baha’u’llah was exiled in Baghdad in 1860 in response to questions of a Sufi Sheik…Shaykh Muhyi’d-Din.
They can be accessed online at
While it may seem arcane to introduce this at this time I think it is important to note that
while Baha’u’llah has cited several works by Attar, Rumi, Saadi and other well known stories it should be noted that as Baha’is we nonetheless do not share the view of some Sufis
An example regarding pantheism:
To recapitulate: the Sufis admit God and the creature, and say that God resolves Himself into the infinite forms of the creatures, and manifests like the sea, which appears in the infinite forms of the waves. These phenomenal and imperfect waves are the same thing as the Preexistent Sea, which is the sum of all the divine perfections. The Prophets, on the contrary, believe that there is the world of God, the world of the Kingdom, and the world of Creation: three things. The first emanation from God is the bounty of the Kingdom, which emanates and is reflected in the reality of the creatures, like the light which emanates from the sun and is resplendent in creatures; and this bounty, which is the light, is reflected in infinite forms in the reality of all things, and specifies and individualizes itself according to the capacity, the worthiness and the intrinsic value of things. But the affirmation of the Sufis requires that the Independent Wealth should descend to the degree of poverty, that the Preexistent should confine itself to phenomenal forms, and that Pure Power should be restricted to the state of weakness, according to the limitations of contingent beings.
~ Abdu’l-Baha, Some Answered Questions, p. 294
Another issue has to do with **obedience of law:
In all these journeys the traveler must stray not the breadth of a hair from the “Law,” for this is indeed the secret of the “Path” and the fruit of the Tree of “Truth”; and in all these stages he must cling to the robe of obedience to the commandments, and hold fast to the cord of shunning all forbidden things, that he may be nourished from the cup of the Law and informed of the mysteries of Truth. 
[1 This refers to the three stages of Sufi life: 1. Shari’at, or Religious Laws; 2. Tariqat, or the Path on which the mystic wayfarer journeys in search of the True One; this stage also includes anchoretism. 3. Haqiqat, or the Truth which, to the Sufi, is the goal of the journey through all three stages. Here Bahá’u’lláh teaches that, contrary to the belief of certain Sufis who in their search for the Truth consider themselves above all law, obedience to the Laws of Religion is essential.
(Baha'u'llah, The Seven Valleys, p. 39)
As to Baha’i views about Catholic mystics there is a paper that was submitted to the Irfan colloquium by David McLean:
As far as official views on Christian mystics I’m unaware of any…but then I’m quite limited.
There have been some works by Baha’is on Buddhist and Hindu subjects…