Had the same confusion between qadr and free will too , take a look at this video , it settles my queries.
If by inherent violence you mean defending oneself then ... yes its inherent violence.
Also our deen has been perfected for us indeed, however the human isn't perfect , u'll find some of the SJW muslims saying the qur'an says nothing evidently bad about homosexuality , whereas the extremists will say that the example of sodom and the punishment given to the residents of sodom is enough evidence exterminate eery gay or gay seeming person who walks the earth.
“As for those in whose hearts is perversity, they follow the allegorical verses, seeking to mislead and seeking to give (their own) interpretation. None know their (i.e., allegorical verses') interpretation except Allah and those who are firmly rooted in knowledge…” (3:7)
Allah uses clear cut verses int eh our;an to lay down the laws and morals , other times he uses Alegorical verses with multiple meanings , the perverse soul (extremists being a perfect example) will go with the interpretation that suits their political and worldly goal , rather than guidance to live by.
here is an essay that talks about this in detail using examples from the qur'an itself.
http://www.quran-islam.org/articles/part_3/allegories_in_the_quran_(P1384).html
This brings me to your last point , answer being simply no , firstly there were 100's of prophets sent since adam till Muhammed peace be upon both , sent to different nations Allah says: And for every Ummah (a community or a nation), there is a Messenger; when their Messenger comes, the matter will be judged between them with justice, and they will not be wronged. (Qur'ân 10:47). Alas people who have not heard the message are distinguishable from those people who REFUSED the message , so why on earth would they be punished if allah said each nation will be judged accordingly , he is all wise all encompassing , you don't need to worry , as for righteous non-muslim believers Allah says Among the people of the Book
there are some who believe in Allah and in what has been sent down to you and what was sent down to them, and who are humble before Allah. They do not sell Allah’s Signs for a paltry price. Such people will have their reward with their Lord. And Allah is swift at reckoning. (Surah Al ‘Imran, 199) , Here Allah recognises that yes there some among the people of the book , jews and christians who are righteous and upright , they will have there reward with there lord and shan't worry. As for the Saudi's corruption and evil is still corruption and evil muslim or not , each soul will be taken care of according to there deeds.
Assuming about Allah without trying to get to know him and understand his message is so sad in my opinion , its sad because here you believe his existence however you failed to recognise his names (also his characteristics) some being , the most wise , the most merciful , the most just in judgement the most compassionate , how can such a god over look the poor 'farmer' or eskimo or tribe in the amazon rainforest for their ignorance and punish them and let the corrupt Saudi off. Try getting to know your creator before accusing him of injustice and cruelty.
Quick fact: Did you know that Buddhism is believed to be the skewed religion of the prophet Dhul Kifl , (this is mostly backed by Ahmadiyyah muslims) i don't think its correct but its food for thought , we know that christianity has been skewed from its essential worshipping of one god , who knows how many dead or alive religions that were once the initial teaching of a messenger sent to a nation of the past. A recent study found that the many tribes of Australian aborigines all (without exception) believe in a one supreme power , who is the first cause of creation, this is an interesting study because, the Australian continent is not only unique in having been completely broken off from the rest of the world, it is also unique in containing within it hundreds of social islands, each comprising tribes that remained entirely isolated from each other. One can only wonder if they (tribes) received a messenger at some point in time (i'm certain of it!).
ps: this is all muddled up i know its 5am here and i;m sleepy but i really felt the need to defend my deen in this one because you were pulling accusations from thin air imo.

also please ask more if you have any , this is a learning process for me too , goodluck