I have two questions to ask.
1.We as a Muslim have a belief that we cannot bow down before any idol, fire etc. but what is the status of Ka'bah as it is also made of stone just like others idols. It is true that we do not bow down before anything in our prayers until and unless we are in front of ka'bah. But the basic philosophy seems to be the same. We bow down before ka'bah from far away but idea remains the same. What is then the difference between us and the followers of others religions? Does not it only mean that they bow down directly and we indirectly? They also say that we are bowing down before idol as a symbol of our respect to God. We follow the same idea. The only difference is that they bow down before many and we bow in direction of one object, ka'bah.
2. What is status of Hazrat Ibrahim regarding the incident of atish-e-namrood? Was he really thrown into fire and that fire lost its heat? Why God did not save his Prophets through normal course of action? Why God always saved the prophets through special help which is not experienced in normal circumstances? For example, Moses was saved by bisecting the river. What is the status of these supernatural incidents?
I am sorry I fail to understand that how one can interpret the Muslim act of bowing in direction of the ka'bah as bowing before the stones when they never do so with the intention of bowing before the building. They only, as you said, take it as a monument of tawhid and a symbol of worship to one God. The difference I see between the idolater and the Muslims can be seen in the fact that the Prophet (sws) did not allow the people to worship the idols which were even set in the Ka'bah. I believe that if followers of a religion other than Islam bow before an idol taking it to be the aya of one God that cannot be objected to and declared polytheism. For examples the Jewish and Christian practice of worship is not idol worship. I would request you kindly to elaborate upon your understanding with regards to the similarity between the idol worship and bowing in direction of the ka'bah. Please shed some light on the clear intention of the Muslims and also that of the idol worshippers.
The Qur'an clearly states that the incident you refer to actually happened. I believe that the Almighty showed miracles and helped His Messengers in a way that clearly showed that God was with them. It then served as a clear argument in the favor of the religion of God.