Has the original post question actually been answered because it looks like the topic derailed and was 'deflected' from the first page.
I'd like to take a shot at the whole question but not gonna put a lot of effort because my answer will likely be buried. Anyone curious can PM me if you want to get into a Islamic/religious debate; I did my share of Islamic history studies.
For context, the Quran was not released as a single scripture from front to back. It was released in several parts orally and written down by different people over different periods before they were cross checked and unified into a book after Muhammad's death. It's not chronological... the first sura is at the end of the book and so on.
At the time, there was a lot of warfare. Muhammad was attacked, nearly assassinated, driven from his home city. He established a city-state, was under continuous raids, attacks, sieges. Eventually he fought back, set up truces and alliances, was betrayed several times, and only got security by conquering the Arabian peninsula. Even then, the Romans and Persians worried about its sudden massive growth (very similar to how Iran, Israel, USA, Russia worry about ISIS now). There were some skirmishes between the Romans, Persians, initial Muslims which led to full fledged battles and conquest.
It's a bit odd to say that they conquered in self-defense, but in this case offense was the best defense. They treated the people they conquered fairly well though, otherwise there would've been a lot of uprisings.
There wasn't even a name for the state/country that Muhammad established. It was just called the Muslim State, had a solid black flag. Abu Bakr, its second leader, was given the title of "Leader of the Believers", not exactly "Caliph" as people often say. A lot of the terminology used today (Rashidun, Abassid, etc) is used to differentiate the different 'mandates' of their leaders but it was initially nameless.
"Kafir" in many of those verses don't translate directly
into disbelievers. There were basically a few sides, the Muslims, the Abrahamic allies, and the disbelievers. It didn't mean disbeliever in the sense of someone in Japan who did not believe in Allah; it meant your typical Arabian polytheist who wished Muhammad dead. It was a cover all term for "your enemies" since 100% of the believers were allies of Muhammad and so were many of the Jews/Christians in Arabia.
It was a theology. Muslims owned and governed their lands. Non-Muslims were pretty much non-citizens who paid tribute in the form of Jizya in return for protection, exemption from wars, and the use of Muslim facilities. Apostasy was punished by death because it was like becoming a citizen to dodge tax and then repealing citizenship - it was a form of treachery, which was punished by death.
It's hard to explain because back then there was little notion of nationalism. Nationalism was replaced with religion. Wars were common so they switched lords often, much like how an employee today serves different bosses. But few switched their God(s). And to switch to one and then switch back was treachery.
If I'm wrong here, correct me, because I'm pulling in a lot of things from memory, can't really be bothered to cross check with Wikipedia or whatever.
So no, it's not a religion of peace. It's not a religion of violence either.
It's more like be nice to people who are of different religions, treat them as guests but not as family. But if they mess with you, harass you then give you some BS, punish them.
To counter the quoted verses, there's Sura 109
, one of the major ones, which boils down to "To me is my religion and to you is yours." You could also look historically at how non-Muslims were treated - they gave refuge to the Jews during a time when Europe hated Jews.