The answer
As far as baptism is concerned, it consists of two parts. The first of which is the blessing of the baptismal water, which is a long ceremony, and can take an hour to perform. The second part, is the actual baptism of the child or adult, which may take only a few minutes.
What happens is that the priest might pray over the water very early on, before the arrival of those in the baptism party, so because they have not attended this part of the ritual they might think that the baptism has just taken a few minutes to perform, whereas if they had been present from the very beginning, it would have taken more than an hour. Therefore what you
imagined to be shorter version of the ceremony was in fact a part of the full-length baptism ritual.
As far as the Mass is concerned, though, there are prayers which are fundamental to the consecration of the Host, such as the signing with the cross, Christ's covenant with us, the invocation of the Holy Spirit, the division and distribution, and the final confession. But the intercessions, for instance, and the commemoration of the saints, the sermon and the various readings are not connected with the actual consecration of the sacrament, but are nevertheless recited as part of the liturgy of the Mass, which is after all the holiest of the services in the Church.
In the time of the martyrs, during the persecution of the Church, the Mass was abridged without any damage being done to the sacrament. Also one can shorten it by abbreviating or eliminating some of the chants, for the music isn't part of the consecration of the sacrament but serves to deepen the spirit of prayer. So don't be apprehensive or suspicious about the validity of the shorter Mass, because the sacrament is still being fully carried out.
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Thrice-Blessed Pope Shenouda III of Blessed Memory