Reply to the original two questions:
1) In the article
"Confirmation" the Catholic Encyclopedia says this about the
matter of that particular sacrament:
There has been much discussion among theologians as to what constitutes the essential matter of this sacrament. Some, e.g. Aureolus and Petavius, held that it consists in the imposition of hands. Others, with St. Thomas, Bellarmine, and Maldonatus, maintain that it is the anointing with chrism. According to a third opinion (Morinus, Tapper) either anointing or imposition of hands suffices. Finally, the most generally accepted view is that the anointing and the imposition of hands conjointly are the matter. The "imposition", however, is not that with which the rite begins but the laying on of hands which takes place in the act of anointing.
It also says this about the Eastern rites:
The Eastern Church omits the imposition of hands and the prayer at the beginning, and accompanies the anointing with the words: "the sign [or seal] of the gift of the Holy Ghost."
The conclusion is that according to the generally accepted view the imposition of hands is part of the essential matter in the Roman rite, and in the Eastern rites it is not.
Therefore, when a bishop confirms in the Roman rite, that means it is essential for validity that he imposes his hands on the head of the confirmants.
It is clearly visible in some of the photos that Bp. Faure touches the head of the confirmant with only his thumb, and that his other fingers and his palm do
not touch the head of the confirmant, which means that there is no imposition of hands.
Because of that, it is possible that it is necessary to
conditionally confirm all those people from Minas Gerais. This
must be brought to the attention of those with greater knowledge of "de defectibus", who could then make a more secure judgment.
Regarding the case Matthew mentioned, of a priest who said "Ego te baptizmo..." (I
baptism you...) instead of "Ego te baptizo..." (I
baptize you...) the question is whether the alteration caused the meaning of the form to change (according to Art. 20 of the "De defectibus" of the Council of Trent) - if it did, the sacrament was not conferred. This is again something which
must be brought to the attention of those with greater knowledge of "de defectibus".
2) Depending on whether the Resistance bishops recognize the 1917 or the 1983 Code (I don't know - does anyone know which they recognize?), according to the 1917 Code (Canon 782) an ordinary priest can
only validly confirm if he receives an indult from the pope, while according to the 1983 Code an ordinary priest can
only validly confirm if he receives an indult from his ordinary or in danger of death.
If the Resistance bishops recognize the 1917 Code, then they are unable to give permission to confirm to priests, since only the Apostolic See can do that, so
any confirmation administered by those priests would be invalid.
If the Resistance bishops recognize the 1983 Code, then they are also unable to give permission to confirm to priests, because only diocesan bishops and other prelates with ordinary jurisdiction can give that permission, and traditionalist bishops do not have jurisdiction, so
any confirmation administered by those priests would be invalid.
These are the relevant canons of the 1983 Code:
Can. 882 The ordinary minister of confirmation is a bishop; a presbiter provided with this faculty in virtue of universal law or the special grant of the competent authority also confers this sacrament validly.
Can. 883 The following possess the faculty of administering confirmation by the law itself:
1/ within the boundaries of their jurisdiction, those who are equivalent in law to a diocesan bishop;
2/ as regards the person in question, the presbiter who by virtue of office or mandate of the diocesan bishop baptizes one who is no longer an infant or admits one already baptized into the full communion of the Catholic Church;
3/ as regards those who are in danger of death, the pastor or indeed any presbiter.
Can. 884 §1. The diocesan bishop is to administer confirmation personally or is to take care that another bishop administers it. If necessity requires it, he can grant the faculty to one or more specific presbiters, who are to administer this sacrament.