# 1. "I know (or think at least) that Allah is their God and Muhammad is his prophet and the Koran is their holy book"
a) Allah is the name of God that the Muslims call him by.
Also Arabic-speakers of all Abrahamic faiths, including Christians and Jews, use the word "Allah" to mean "God". The Christian Arabs of today have no other word for 'God' than 'Allah'. Arab Christians for example use terms Allāh al-ab (الله الآب) meaning God the father, Allāh al-ibn (الله الابن) mean God the son, and Allāh al-ruh al ghodus (الله الروح القدس) meaning God the Holy Spirit .
b) Muhammad(saw) is not the Only Prophet.
But the Last Prophet.
Prophets also include - Adam, Enoch, Noah, Solomon, Lot, Moses, Zachariya, Jesus, and still many more.
# 2. "Why do some Muslims hate and want to kill infidels and some say that the Koran teaches a peaceful religion?"
Muslims do NOT hate anybody be them even Infidels.
The only thing is that they just as All other religions claim that the Non-Believers have wronged themselves and that if they die with their believes they might be to Hell.. Same what any other religion Speaks about.
(..So its all the same and there is nothing new, rather than exaggerating a peck).
--Muslims Don't Want to Kill any Infidel.
(..Had this been so you couldn't have met a Single Muslim in your life Safely.)
**So Its NOT that**
When the Verses of the Qur'an are read or refered:
002.190 Fight in the cause of Allah those who fight you, but do not transgress limits; for Allah loveth not transgressors."
And to be more Precise the Muslims will fight only when they are on the Battle ground.
Also,
002.193 And fight them on until there is no more Tumult or oppression, and there prevail justice and faith in Allah;
but if they cease, Let there be no hostility except to those who practise oppression.
002.217 ....Say: "Fighting therein is a grave (offence); but graver is it in the sight of Allah to prevent access to the path of Allah, to deny Him, to prevent access to the Sacred Mosque, and drive out its members."
# 3. "Who are infidels anyways?"
Infidels are the Ones who do not believe in Allah..
and His sent Messengers.
The word Infidels may not Include Christians and the Jews.
(..Niether does a Muslim, or a Jew, or a Christian, or a Buddhist ever Jump to kill Anybody, Just for being of the Religion he/she is of.)
That as another part of the Muslim faith is a grievious "Sin".
And thus also as a matter of being a Human nad Believing in Allah a Muslim "should" not kill.
I say "should" because there are still who abuse, fight, steal and rob and drink and all.
Its all about some of the Blacksheeps of the Society.
# 4. "Do all Muslim women not show their face? Why or why not?"
NO, its just about How much does a Muslim Practices the faith.
And also the Covering of the face of Muslim Women does Not include the Covering of the Face, though some out of Ignorance do practise it.
To protect the women's modesty there are references for a woman to Put on a Cloak when She is Out.