It would, perhaps, be more correct to say that the Triduum is one celebration, beginning with the Mass of Institution of the Lord’s Supper on Holy Thursday and continuing through the Easter Vigil Mass on the eve of the First Sunday of Easter.
Next, there really are no parts that I would suggest that anyone should skip in the Easter Vigil. The celebration of the Vigil Mass begins with the lighting of the new fire, the procession of the candle, the singing of the Exsultet. The readings from the Hebrew scriptures - the proclamation of Salvation History are not separate from the Mass, but an integral part of it.
While it is true that the singing of the Gloria and the Opening Prayer take place after all of the readings from the Hebrew Scriptures (some of which are required at the service), this is not the beginning of the celebration. The celebration has been ongoing.
Now, my $.02. Yes, it can be long. Yes, it usually includes incense (I enjoy it!), but if you are not looking for that celebration, the other Masses are available. However, the Vigil Mass is the Mass from which we draw for all other celebrations. It is the Mass at which adults who are coming into the Catholic church, the one true church, are baptized or received, receive the Eucharist for the first time and are confirmed. It is the high point of the church’s year. I would encourage everyone to at least experience it once.