Contacting the blood of Christ in immersion

Does one really contact the blood of Christ in immersion? The bible never says that. But if baptism washes away sins, since only the blood of Christ can wash away sins, we can conclude (falsely) that in immersion we contact the blood of Christ.
My objections to it are given below.
1) Why doesnt the bible explicitly mention something as important as this?
2) 'To be washed by the blood of the Lamb' is symbolic of the fact that ones sins were paid by the life of another. 'The life is in the blood'. If 'washing away ones sins' is symbolic of Christs death then why cant the whole process of baptism be symbolic? The Israelites never washed themselves in the blood of their sacrifices. They had faith that God had somehow transfered their sins onto the Lamb. In the same way, just as the Israelites looked forward to Christ on the cross, we look backward to Christ on the cross.
3) Christ is no more flesh and blood, so how can one contact Christs blood in immersion. Does he magically go back in time 2000 years ago and contact his blood on the cross while he is being immersed?
4) Why would God unite sinners to Christ on the cross. Wouldnt that make Christ, the unblemished Lamb, blemished. Hence Christ could not be an acceptable sacrifice before God, if sinners were united with Him. Christ paid for our sins on the cross, he didnt take upon himself our sins and become a sinner on the cross.
5)Baptism refers to death, not life
6)Did Abel,Enoch,Noah,Abraham,Issac,Jacob,...,David,...etc. contact the blood of Christ? According to the coc they must have. How did they contact the blood? They werent immersed. Does God have an 'if you lived before Christ, you have contacted the blood(somehow) but if you live after Christ you have to be immersed to contact the blood of Christ' rule? Is God a 'God of exceptions' and if-then rules?
7)The thief on the cross was forgiven before Christ died, but died after Christ. Under what covenant did he die? Didnt he die under the new covenant? Shouldnt the new covenant apply to him? Or was there a gap of 50 days between the old and the new covenant where anyone who died within that period can write their own plan of salvation?