amariselle, I'll answer these questions for you.
Well that is what we human beings do is it not? Have you ever been to Washington DC? Or for that matter other seats of government? Washington DC has monuments all over the place built to memorialize those giants in our history. We don't worship Abraham Lincoln, or George Washington, or even objects such as the Liberty Bell or the Constitution. We as a nation has memorized them because they are important to who we are as a nation. I should point out that when all of these things were erected the far majority of people in this country were Protestant.
Don't we have cities, counties, villages, etc. named after war heroes, and societal giants?
Quite honestly not often before, as most people pray in their homes; anyway that being said two things: 1) We believe we can pray to Mary and the other Saints because we believe they are alive, and we believe that God gave them the power to hear our prayers. I think the confusion here with non-traditional Christians is that prayer and worship has become synonyms where traditionally they were (and still are) not. We see many instances in Scripture where men and women dialoguing with angels, and we even have an incidence at our Lord's transfiguration where He Himself is dialoguing with Moses and Elijah.
Now concerning before images and statues. Christians have long used images and statue, and other sacred art as focuses in prayer. Praying in a sacred place where not just the mind but also the eyes, ears, nose, etc are engaged makes prayer so much easier for so many of us. This I believe can be proven very easily.
Concerning sacred images and statues, they are held at a higher level of respect and honor than mundane objects because of the very fact that they are seen as tied to God. This isn't unique to Christians, but you also see the same in Judaism. When reading the Old Law, there was a lot of attention given to how to handle sacred objects appropriately.
I talk about the Mediatrix of all graces. First you are right Jesus Christ alone is the mediator between God and man. This we will not disagree with you. The question is what about between Christ and man? Many, many times we Christians are asked by either our fellow Christians or even those who aren't for prayers, to assist a family member that is extremely ill or injured, or going to a job interview, or many other things. Are we in these cases acting as mediators? Of course we are. Mary also acts as a mediator between Christ her Son and man. We have seen her in Scripture mediate between Christ and man at the wedding feast of Cana. We believe Mary is in heaven with her Son, and thus being His mother has a little bit more influence with Him than we do.
Even in St. James we read: 5:16 Confess your faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.
17 Elias was a man subject to like passions as we are, and he prayed earnestly that it might not rain: and it rained not on the earth by the space of three years and six months.
18 And he prayed again, and the heaven gave rain, and the earth brought forth her fruit.
So we know that the righteous' prayers are more effective than others, straight from Scripture.
The second part "of all graces", this one requires an understand of who the Blessed Mother is. The question raised is where do all graces come from? From the Holy Spirit through Jesus Christ right? But Mary gave birth to Jesus Christ and because of this one can say that "all graces" come from her because Jesus came from her. See the point here? So the title Mediatrix of All Graces actually says more about us human beings sharing in Mary's ministry of mediating for our fellow man before our Lord, and says more about her Son, by whom we receive all grace.
Alright Queen of Heaven. This requires one to understand the offices of the Davidic Kingdom, which Jesus comes from the line of Davidic Kings. In Israel the queen was not the wife of the king, for the king would have multiple wives. Rather the queen (or another title used queen mother) was the mother of the king, and her importance and authority in Israel was second only to the king. The office of queen mother and its establishment is attributed to King Solomon and is found in 1 Kings: 2:19 Bathsheba therefore went unto king Solomon, to speak unto him for Adonijah. And the king rose up to meet her, and bowed himself unto her, and sat down on his throne, and caused a seat to be set for the king's mother; and she sat on his right hand.
20 Then she said, I desire one small petition of thee; I pray thee, say me not nay. And the king said unto her, Ask on, my mother: for I will not say thee nay.
So when we say Mary is the Queen of Heaven, we are also saying that Jesus her Son is King of Heaven. For if Mary is not queen of heaven then neither is Jesus king of heaven. Hopefully you see the point. The same applies to the title of Mother of God. If Mary is not the mother of God, then that means that Jesus is not God. They both go hand in hand, and you cannot separate either without falling into heresy.
I can understand. Americans and many modern folks don't bow to no one anymore. This is a custom that has ceased to exist in the modern world. In ancient and even just a few hundred years ago prostrating or bowing down yourself was common practice to display humility. Mankind has lost much of its humility, sadly.
I don't know what you would call how St. Elizabeth attitude toward here in Luke 2.