At this point it's probably worth noting that I am an ex-Muslim. I am familiar with everything you just said.
It those who receive and understand properly the message and teachings of Islam and then reject and deny it that have issue.
The problem with this is the absurd implication that Islam is obviously true to anyone who understands it well. There are plenty of people who understand Islam very well and still don't believe that it is true, including numerous notable scholars of religion and the person you are talking to right now.
Muslims who do bad deeds and have many un-repented sins and few good works can go to hell, however their stay will be finite. Anyone in Hell who had faith will be there for a finite period.
So, yeah, /u/EvanYork was accurate in saying that in Islam people are saved by a combination of faith and good works. Your good works count for little if you do not accept the Islamic faith.
As for non-muslims in hell. Many people say they will be there for infinity, but others say hell will be finite for everyone, so eventually, after an immense time, others will eventually make it. I am in the latter camp.
This sort of resembles the ideas of purgatory in the Catholic tradition, which also asserts that people are saved through a combination of faith and works, further supporting the accuracy of what /u/EvanYork said.
The Qur'an is clear god can and will take people out of hell (6:128 and 11:107). His mercy encompasses all things (7:156). His mercy also prevails over his wrath.
Qur'an also talks about Jews and Christians in heaven in 5:69.
Good works matter for all (99:7-8).
This is the exact sort of flawed "mercy of God" argument that I was talking about. You're overlooking the various and numerous parts of the Qur'an that make it clear that these rules of potential mercy "if God wills" are only applicable to those who accept the creeds preached by Muhammad (AKA the articles of faith).
5:69 is talking about only those Jews or Christians who believe in Allah (i.e. God as described by Islam, not the Holy Trinity or the God who prioritizes the people of Israel), meaning the heretics of those religious traditions. The Qur'an attacks my Trinitarian Christianity several times so this verse is clearly not talking about me and my brethren in faith. Likewise, 99:7-8 is only talking about Muslims, as the Qur'an is clear about the fate of those who reject Muhammad's specific message: a painful punishment, wherein they will abide eternally. The only way you can extend the mercy of God in Islam to non-Muslims using your oft-quoted verses as support is if you assert that He is lying in many other parts of the Qur'an.