There are over 900 million Protestants worldwide. The largest Protestant denomination seems to be Anglicanism with 85 million members, followed by Baptist, Lutheranism, Methodism and Calvinism. Another consideration is the denominations that make up “Modern Protestantism” – 400 to 500 million. Then we have non-denominational / evangelical Protestants – 80 to 100 million. And then there are the 35 million members of non-Trinitarian denominations. Source: https://en.wikipedia.org/wiki/List_of_Christian_denominations_by_number_of_members#Protestantism_%E2%80%93_920_million
Asking what are the views “in Protestantism” about equality, worth and respect, is therefore problematic because some denominations may subscribe to more liberal views than others. To find out what one specific denomination believes, you would need to examine their official Statement of Faith and drill down to find what each has to say on the topics you mention. However, it is possible to take a biblical overview – a generalisation – in order to establish what Bible-believing Protestant denominations should adhere to. As a Christian of the Reformed Protestant persuasion here is my response to your questions:
Yes, Protestants understand that we are all equal under God. It doesn’t matter if you are a King or a Queen, a President or a pauper. The basis of equality has to do with how God views us. God is holy, righteous and just and the sad truth is that every person is born with a sin nature. The hard truth is that we have all sinned (Romans 5:12) and if we claim to be without sin we have deceived ourselves (1 John 1:8). In that sense, we are all equal under God.
However, I suspect what you are really asking is how Protestants view other people. Do they see everyone else as being equal? Do they think some people are of higher worth than other people? Do they believe that everyone deserves equal respect?
Do Protestants see everyone else as being equal? Yes, whilst understanding that no created being can ever be equal to God (Isaiah 40:25).
Do Protestants think some people are of higher worth than other people? No. On the contrary, according to Philippians 2:3, we should “do nothing out of selfish ambition or vain conceit, but in humility consider others better than ourselves”.
Do Protestants believe that everyone deserves equal respect? Christians are told to show proper respect to everyone (1 Peter 2:17). That includes showing respect within the family, to employers, to government officials, to rulers. Those are people who deserve respect.
Ultimately, the bottom line is that it is God alone who is worthy of our respect (Malachi 1:6) and Protestants seek to follow the example of Christ Jesus in their dealings with other people.
Edit in response to clarification from OP: Jesus said the most important command is to love the Lord our God with all our heart, soul and mind. The next, like it, is to love our neighbour as we love ourselves (Matthew 22:37-39). That means our actions are to be motivated by our love of God and our love of others. If we say we love God then we are bound to show Christ-like love for other people, regardless of their age, race, gender, origin of birth, skin colour, or state of health.
We should respect all people, remembering that we are all created in God’s image, regardless of our religious beliefs (or non-belief). Take the example of the “Good Samaritan” in Luke 10:33-34, who went to extraordinary lengths to help the Jewish victim of robbers, even though the Samaritan himself was despised by the Jews.
Christians are advised to follow the example of the Apostle Paul who said:
I try to please everybody in every way for I am not seeking my own good but the good of many, so that they may be saved. Follow my example, as I follow the example of Christ. (1 Corinthians 10:33)
If we claim to be followers of Christ Jesus then we are bound to walk in his footsteps, to show compassion to the lost, the dispossessed, widows and orphans, to visit the sick and to care for those in need. There is no room for discrimination.