Wyclif is a true reformer, that had not happened, however,, because the reforms he proposed were united in ecclesiological errors and Eucharistic and violent controversy. What is certain is that Wyclif, in his criticism of the Church of the time, Central to the development of the Avignon papacy and the Church's institutional situation with abuses related, He had well individualized system to correct deviations and to delete:
the separation of the clergy from the state
correction system beneficiale
the reform of the clergy (pastoral care aspect).
The ideal is to inspire the Apostolic Church or otherwise pre-Constantinian. Wyclif also takes as its reference point the archetype of the Church (eternal, immutable, existing in God) that does not depend on existing Church. This is the true Church: therefore easy to reach the conclusion that the Church of his time had no value, because it did not correspond to the archetype. Wyclif also proposed concrete reforms against the decadent and devotion against the decadent life of the clergy, putting as a reference point the Gospel.
The Bible is not only the foundation of faith, but also the only true and absolute truth. It is the word of God, true in itself, that contains all the truth that you can learn about (even in its literal expression): therefore it should be taken as it is. It is the parameter of all knowledge and all conduct: from here, so that only what is right according to the Bible is true.
This principle does not amount to Sola Scriptura Luther, Wyclif because he admits the interpretation of the Fathers (especially Augustine) and Doctors recent (Anselmo, Hugh of St. Victor).
The true Church is the predestined, composed of the elect of God from eternity and free: they can not get lost. They can sin mortally, but the grace of predestination that you can not lose and that will save them. The true Church is there where there are the elect.
The denial of the papal primacy comes only in the writings following the Great Schism of 1378.
After the Schism Wyclif tries to show that there is the need for a pope in the Church, that there is not even a Roman primacy and power of the cardinals to elect a pope.