My friend, you ask excellent questions.
I would say the dead believers are alive. And I would say that they are with the Lord Jesus.
Mat 22:29-32 29 Jesus answered and said unto them, Ye do err, not knowing the scriptures, nor the power of God.
30 For in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven.
31 But as touching the resurrection of the dead, have ye not read that which was spoken unto you by God, saying,
32 I am the God of Abraham, and the God of Isaac, and the God of Jacob? God is not the God of the dead, but of the living.
I would point out the words "are as the angels of God in heaven...". We do not become angels, we just gain access to their heavenly realm. With eternal life, we no longer need to perpetuate ourselves through marriage. Also angels are not omniscient, otherwise Satan would destroy every one of us.
2Cr 5:6-8
6 Therefore [we are] always confident, knowing that, whilst we are at home in the body, we are absent from the Lord:
7 (For we walk by faith, not by sight:)
8 We are confident, [I say], and willing rather to be absent from the body, and to be present with the Lord.
Ok.
Are the dead believers, who are alive, in the Body of Christ?