As already stated, the word Muslim means submitter or to submit.
So when Islam says that Abraham, Jesus and all the Prophets and Messengers that God sent to mankind are indeed Muslim we mean by that that they Submitted to their Lord and carried the unique message of One God, or tawheed. And that is indeed the same as the Muslim living somewhere like Egypt, since that Muslim has embraced Islam which carries that message for all mankind till the Day of Resurrection.
They did indeed come with the same message from the same God. Only difference between the previous prophets and messengers God sent and Muhammad is not actually what you mentioned.
Rather it is that Muhammad (pbuh) was sent down to ALL mankind until the Day of Judgment and is a seal to all prophets. Whereas the others noble prophets/messengers were sent to their nations or peoples.
Mohammad (PBUH) was only set down to perfect manners.
"The only reason I have been sent is to perfect good manners."
Allah subhaanahu wa ta ‘aala starts off Surah Al-Qalam, an early Makkan surah revealed to defend the status and honor of Prophet Muhammad sal Allaahu alayhi wa sallam by saying:
And indeed, you are upon a noble conduct, an exemplary manner (Al-Qalam 68/4).
The comparison you make is off-balanced. The battles that were held in the name of Islam were indeed noble battles that were
1) to regain their property, ie. when they were forced out and when to make hijra, migration, they later came back and retook their own homes and property
2) to gain freedom for the peoples to worship however they wanted, ie some villages would not allow or humiliated Muslims so leaders from around would fight for those Muslim's rights and when justice was restored everyone was allowed to worship what they willed.
3) and ofcourse that of self-defence, ie when the tribe of Jews did not honor the peace treaty made between them
There could be more or if I said something inaccurate I hope a fellow Muslim(ah) could correct me inshaAllah.
http://www.khutbah.com/en/sunnah_seerah/manners.php
Now in reality, the Prophet Muhammad (pbuh) only killed in his entire lifetime ONE person. by the name of Ubay ibn Khalaf.
http://mac.abc.se/~onesr/d/fwi1_e.pdf