Compositional anaylsis of the Gospel of Mark

[Undeceived]

When does the NT claim he was so marred that he was unrecognizable as a human?

Criminals were beaten half to death before they were crucified.

Isaiah 53:3 contains, “A man of suffering, familiar with disease.”
Isaiah 53:10 states, “But the Lord chose to crush him by disease”

When does the NT say Jesus was diseased (the Bible only refers to Leprosy as disease)?

The Hebrew word "ḥō·lî;" here translates more closely to "grief".
http://biblos.com/isaiah/53-3.htm

Isaiah 53:10 also states, “That, if he made himself an offering for guilt, he might see offspring and have long life”

What passages in the NT mention any of the following: Jesus made a guilt offering, he had offspring, he had a long life?

The guilt offering is a sacrifice for sins, usually a ram. But here it says "he made himself an offering for guilt" predicting Jesus' own sacrifice. Jesus had offspring in terms of spiritual progeny (we're talking a spiritual Messiah here). He will also live and rule forever, as Isaiah 9:7 reads, "Of the greatness of his government and peace there will be no end. He will reign on David’s throne and over his kingdom, establishing and upholding it with justice and righteousness from that time on and forever." Mark 16:19 is the fulfillment. As you have undoubtedly noticed, no normal human can fulfill these criteria.