I'm not sure what caused the new post to an old thread, but since this popped up I stopped and read it. Just want to comment on the issue as to whether or not the Catholics would be likely to accept the ordained status of an Orthodox presbyter who was out of communion with his own former Church - and, unfortunately, the answer is generally "yes".
The theological praxis of Catholics and Orthodox as to the validity of orders and the dependent issue of the validity of sacraments differs significantly.
There are basically two theories of apostolic succession and, in most instances, the application of the theory held by a given Church effectively determines the validity accorded to claimed presbyteral and episcopal orders and, ipso facto, the validity of sacraments administered by those claiming to possess valid orders, whether presbyteral and/or episcopal (putting aside issues as to form and intent, since if there is no validity to the orders of the sacrament's minister, other considerations are of no consequence to either Church).
If the orders claimed to be possessed are themselves invalid, the sacraments derived from him who claims to possess orders will, in turn, be invalid if the sacrament is one which requires administration by an ordained minister - essentially any except baptism in extremis in either the Catholic or Orthodox Churches and marriage in the Latin Church, which deems the couple to be the ministers and the presbyter to be a witness.
The Augustinian theory effectively holds that valid episcopal ordination confers an indelible character that is not affected by any schismatic or heretical act or excommunication taken in response thereto or for any other reason. Accordingly, a validly ordained priest once validly ordained to the episcopate retains his capacity to exercise that order, though he may have been deprived juridically of the office or jurisdiction by which he performed episcopal acts. The latter considerations affect only the licitness of his acts.
The Cyprianic theory effectively holds that a valid episcopal ordination is affected by schismatic or heretical acts and by excommunication taken in response thereto or for any other reason. Accordingly, a validly ordained priest once validly ordained to the episcopate retains his capacity to exercise that order only so long as he continues in communion with the jurisdiction under the authority of which he was ordained to the episcopate (or such other jurisdiction into which he may have subsequently been accepted) and is exercising the office or jurisdiction by which he has the right to perform those acts. There is no distinction made as to licitness.
The Catholic Church adheres to the Augustinian theory; the Orthodox Churches to the Cyprianic theory, (although the latter have been known to exercise oekonomia in application of it to instances in which schismatic bodies have returned to communion).
Frankly, the Augustinian theory has been or certainly has become a thorn in the side of the Catholic Church. It effectively assures that all manner of independent hierarchs, both those who pursue their perceived vocation with spiritual and intellectual honesty and those who are episcopi vagante in the most perjorative connotation accorded to the phrase, can sleep at night with at least a modicum of assurance that they possess valid episcopal orders, unless form or intent are at issue. The time-honored practice in the so-called "independent" Catholic and Orthodox movements of garnering multiple episcopal consecrations or, subsequently, being re-consecrated sub conditione is effectively a means of leveraging the Augustinian theory.
Most such hierarchs operate on the premise that "more is better" or "there has to be at least one good one here somewhere". With most having an episcopal genealogy that traces back through an average of 30 ancestral lines of succession, from a combination of dissident Latin Catholic, Eastern and Oriental Catholic, Eastern and Oriental Orthodox hierarchs, they can feel reasonably secure. Those lines which cannot be proven valid because there is serious doubt as to the validity of one actor (e.g., the so-called Melkite-Aneed Line) can and do feel comfortably buffered by Duarte and Thuc Lines.
People sometimes point to subsequent acts by bishops of these "Churches" which break faith with Catholic doctrine and erroneously perceive these as breaking the line of apostolic succession. For instance, no bishop, regardless of the validity of his episcopal orders, can validly ordain a woman. But, that he did so would not invalidate his subsequent ordination of a man, with proper intent and according to proper form. So, it is possible to go rather far afield theologically yet still retain apostolic succession.
None of this is to say that all such entities have valid orders or sacraments. As an example, the Liberal Catholic Church is certainly suspect, but an inordinate amount of effort has to be put into tracing and verifying or rejecting such when presbyters or hierarchs of these Churches are received into communion.
The Orthodox Churches, relying on the canonically legal status of the hierarch conferring orders (his status in communion with a recognized jurisdiction to which the Church accords canonical status), have a much simpler task before them in assessing validity and, since they do not make the distinction of licitness, the end result is clear-cut.
Given its historical ties to the Cyprianic theory, it stands to reason that the Orthodox would not accord validity to Catholic orders or sacraments and that any do so must be seen as an exercise of charity or oekonomia on their part, applying a measure of recognition to the common historical origins of Catholicity and Orthodoxy.
The potentially most ironic consideration here is that, applying the Augustinian theory, the Catholic Church in some instances could likely find itself in the position of accepting the validity of presbyteral and episcopal orders, and, consequently, sacraments, of "independent Orthodox" (and by that I do not mean those essentially mainstream Orthodox Churches which are typically termed "non-canonical" or "of iregular status", but those of the so-called "independent movements") whom the Orthodox themselves would, rightfully, never deem to be of their Communion, under even the most liberal of interpretations.