You seem to be forgetting that the feasts were given to Israel, not to the Church, and not to Gentiles. The feast of tabernacles is very specific: Ye shall dwell in booths seven days; all that are Israelites born shall dwell in booths: (Lev 23:42) So if you are not a direct descendant of Abraham and know to which tribe you belong, it would not be applicable.
Furthermore, in order to observe the feasts according to God's commandments, (1) the Levitical priesthood would need to be in place, (2) the temple would need to be in place, and (3) the animal sacrifices would need to be performed as specified:
Seven days ye shall offer an offering made by fire unto the LORD: on the eighth day shall be an holy convocation unto you; and ye shall offer an offering made by fire unto the LORD: it is a solemn assembly;and ye shall do no servile work therein. These are the feasts of the LORD, which ye shall proclaim to be holy convocations, to offer an offering made by fire unto the LORD, a burnt offering, and a meat offering, a sacrifice, and drink offerings, every thing upon his day: (Lev 23:36,37)
Do you see why this feast cannot be observed any longer? And the Law of Moses is very clear. If you do not do everything as it is written, you come under a curse.
As to connecting this feast with the Second Coming of Christ, there is no Scripture which actually makes this connection. Furthermore, the apostles (and by extension the Church) were told to focus on the Great Commission, since they were not to know the times and the seasons when God would restore the kingdom of Israel on earth (which will happen after the Second Coming:
And he said unto them, It is not for you to know the times or the seasons, which the Father hath put in his own power. But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth. (Acts 1:7,8)