I'm willing to listen then. Why did Jesus leave, never to return? It seems like a broken promise to me.
The
parousia is part of the promise. Look it up.
He is alive.
Where your error begins is in treating him as Man, not as divine being. The general Christian position (Christology wise) is that Jesus was both man and divine being (the Copts were notable in disagreeing to this in the early days, but there were others), and immersed himself in the flesh to set an example of love and sacrifice for one another --to show the way, as it were.
One way to see His miracles was as a way of getting peoples' attention to the deeper message. There are other ways to view them, about which volumes have been written.
Christian theology posits Jesus as active in his participation in salvation via the person of the Holy Spirit (part of the Trinity) which he passed to the Apostles at Pentecost. Some of the more charismatic devotees and sects take it a bit further, putting Jesus as very much alive and accessible in daily life. For the denominations who treat the wine and bread, consecrated, as The Real Presence during communion (Greek Orthodox, Anglican, Catholic, Lutheran, Syriac, others) Jesus comes alive to the faithful at each celebration of the formal worship. (IIRC, the oldest record of this sort of eucharistic celebration is the liturgy of St James in the first or 2d century, but I may be forgetting something).
Even without that position of belief, "He's alive" is a common refrain among the Evangelicals in the Protestant denominations.
See also the old form of the RCC doctrine:
Christ has died, Christ has Risen, Christ will come again. (In English. It comes off differently in the Latin and in other tongues. That is part of why that English phrase was changed to fit the more literal rendering of the promise made, summed up as "until you return to us." If you ever wondered at why Tolkein entitled his last volume "The Return of the King" it is well to recall that he was a lifelong, devout, and practicing Catholic. Subtle he wasn't. )
In an abstract way (if you take the teachings of the Apostle Paul as a guide) the Faithful are the Body of Christ on Earth in the here and now.
"Wherever two or more of you are gathered in my name, there I am among you" is one of a number of scriptural and doctrinal positions that establish this relationship. Whether or not you accept this is up to you.
When is the Second Coming? Check the various Rapture Bunny websites for predictions.

Good luck with the guess work. Scripture suggests that his priority consideration is that the faithful keep the faith that He will return ...
Mark 13: 31-24
31 Heaven and earth shall pass away: but my words shall not pass away.
32 But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father.
33 Take ye heed, watch and pray: for ye know not when the time is.
34 For the Son of Man is as a man taking a far journey, who left his house, and gave authority to his servants, and to every man his work, and commanded the porter to watch.
35 Watch ye therefore: for ye know not when the master of the house cometh, at even, or at midnight, or at the cockcrowing, or in the morning:
36 Lest coming suddenly he find you sleeping.
You can make of that what you wish. A variety of analyses and critiques of this chapter in Matthew are available for your consideration, if you'll bother to do the research.
EDIT to add:
ixolite and kopji:
Thank you both for adding to my understanding, and for putting the E into JREF.
