It is a good question and I think the problem comes down more to the word that the KJV has used saying 'touch me not'. The Bible Knowledge Commentary explains saying the following for John 20:17-18.

"She may have embraced Him physically, for the Lord responded, Do not hold on to Me, for I have not yet returned to the Father. Go instead to My brothers and tell them. . . . These words spoke of a new relationship, new relatives, and a new responsibility. Many wanted to "hold onto" Jesus. The KJV translation "Touch Me not," has caused many interpreters to wonder why He could not be "touched." The NIV translation is more accurate, for He certainly was not untouchable (cf. Matt. 28:9; John 20:27). Mary had lost Jesus once before (at His crucifixion) and it was natural to fear the loss of His presence again.

Jesus said, in effect, "This (the physical contact) is not My real presence for the church. A new relationship will begin with My Ascension and the gift of the Holy Spirit to the church." Jesus then explained the fact of the new relatives. He called His disciples His brothers. Earlier He had said they were friends: "I no longer call you servants . . . instead, I have called you friends" (15:15). Believers in Jesus become a part of Jesus’ family with God as their Father (cf. Heb. 2:11-12; Rom. 8:15-17, 29; Gal. 3:26). Mary’s new responsibility was to testify to His risen presence. She was the recipient of four special graces: to see angels; to see Jesus risen; to be the first to see Him alive; and to be a proclaimer of the good news. Christians today are also the recipients of special grace; they too are given this new responsibility to witness to the world (cf. Matt. 28:16-20)."

So there wasn't anything wrong with actually touching Jesus before He had ascended to His Father. The command is better understood not to 'hold onto' Him or prevent Him from leaving again. And as to when He when back to the Father, that is given in the Acts 1 passage that you mentioned.

All the best.