That being said, I felt like (for the most part) the college I attended did a good job at what they do. Here's my take on their position. I tie them in with God's perspective of authority in Romans 13. I know the primary application of that passage is to government, but Paul seems to be pretty generic on the idea of human authority with the phrase "there is no power but of God." Ultimately all authority is exercised at the permission of God. Thus it includes governmental authority, but could also apply to parental authority, employment authority, etc. That being said, what does God say about the role of authority? It is to punish evil. Rulers are a terror (v. 3) and to be feared (v. 4) and they have God's authority to execute wrath (v. 4). Nothing in those verses indicates that God's authorities are to be merciful, compassionate, or forgiving toward those who do wrong. Don't get me wrong. All of those things are definitely expected of the INDIVIDUAL believer, but the "entity" of authority is not under that obligation. I know that sounds hard to reconcile, but maybe this analogy will help...

As a individual, I am not allowed to take the life of another person. "Thou shalt not kill" is pretty clear. I PERSONALLY cannot kill someone. However, what happens when a person commits murder, or some other capital crime? The Bible is pretty clear that capital punishment is appropriate. So who carries it out? An execution is performed under the auspices of human government. The "entity" of government is not expected to "love and forgive" the murderer. Government is expected to carry out God's judgment on the murderer. The authority is not under the same obligation as the individual. So all of the guidelines/verses you referenced in your question admonishing grace, mercy, love, forgiveness, etc., are the responsibility of the individual believers toward each other, but not necessarily the responsibility of the authority God has placed over them.

Please get this. I am not saying that government, a Christian college, or any other authority has a blank check from God to do what they want. All authorities, governments, parents, and Christian colleges, will answer to God one day for how they represented God's authority to those under them. What I am saying, is that you cannot assume that an authority is wrong or unbiblical simply because they enforced a rule or law in a manner differently from the way an individual might treat another person. There are a different set of obligations for God's delegated authorities. Could your school evaluate how they treat offenses? Sure they could. As I said before, I'm not trying to defend all of their actions or policies. I'm just saying that they do have God's permission to enforce their rules, and we have a responsibility to respond properly to those rules.

Perhaps the best passage for this is I Peter 2. Peter admonishes the believers to submit themselves to "every ordinance of man." That word "ordinance" is translated most every place else as "creation." The idea is to submit to the rules that man "makes up" or creates. It is assumed that we will submit to God's laws. Apparently some felt they didn't have to submit to rules that originated with man. Peter says they did, even to the point of their own suffering if that's what it led to. He says they were to do this because God would use their submission to testify of Him. At the end of the chapter, he uses Jesus as the ultimate example of one who submitted to His authority, even to the point of His own death, pointing out that God used that authority's abuse of Christ to accomplish salvation. His example sets a pattern for us.