How wonderful, hope you will get some answers through the reading.
Great questions on the Five Solas. I will try to explain Soli Deo gloria the best I can and let other brothers and sisters develop later on.
To discuss Soli Deo gloria ("glory to God alone") we need first to take a step back in the terms used and see what the meaning of them really are. Why this is important is because whatever our definition of glory is, will affect the way we understand God, and later come to worship him in that glory that he resides in.
The topic can of course be discussed in many different ways, but my journey took course within three head questions, the following:
1:How does God describe his own glory, through scripture?
2:What part has creation to mirror the glory of God, and how has God used creation to show his glory?
3:Why is it impossible to react/comprehend to Gods glory without any involvement of creation?
1 and 2:
1 Corinthians 10:31
So, whether you eat or drink, or whatever you do, do all to the glory of God.
Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.
Arise, shine, for your light has come, and the glory of the Lord has risen upon you.
Blessed be his glorious name forever; may the whole earth be filled with his glory! Amen and Amen!
Looking on the passages mentioned above a protestant might literally go Hallelujah. All glory to God and that´s it. What he/she is doing in that case is isolating the glory of God to a point where it does not reflect what the fullness of it actually means. Looking on the passages there is directly one thing outside of God that is also presented, without many of us noticing it. 1: Response, either by us humans or by creation, or through us, it.
What would our understanding of the glory of God really be but a mystery, if we did not have any way to respond to it, through what Pauls presents, drinking & eating, doing (1 Corinthians 10:31), bowing & confessing (Philippians 2:9-11)?
Or through Isaiahs passage, rising & shining (Isaiah 60:1)? Or through the Psalm, blessing (Psalm 72:19).
Whatever way we look at it. These passages wouldn´t make sense to any human, but only to God and his kingdom, if we took away Gods creation in the question for his glory. His glory surpasses his creation, of course, that is for certain, but how would we really understand the glory of God outside it? If we stick to this mysterious way of looking at Gods glory, we ultimate create a distant God, a Father that didn´t work through creation and time, who didn´t make known his glory to us through the things which he gloriously created, and which He saw was good.
So answering the 3 questions shortly, we can see this just by a few examples I gave, and there are tons of it.
1: Gods glory surpasses all things, he does not need them to show his glory, but he does so for us to understand and react, respond to it.
2: Creation and we are the mirror through which Gods glory is shown, otherwise we have no question to ask. We´re then talking about a God not working in time, and not making his glory apprehensible to us. For even if we take the Soli Deo gloria ("glory to God alone") from a protestant perspective, does we not need a mind to even understand the letters which we discuss? Not a created human and soul through which we can give glory and see it? Therefore, creation is noting terrible in the sight of God, because he made his glory known through it. Why should we humans then not respond back through the persons and things through which God made his glory known? Therefore veneration is given, with ultimate purpose to the glory of God. As we even can see through eating, drinking, or explicitly through Paul(see passage below), and even more through the love and mercy of our Lord Jesus Christ.
11 God did extraordinary miracles through Paul, 12 so that even handkerchiefs and aprons that had touched him were taken to the sick, and their illnesses were cured and the evil spirits left them.
3: Looking back at the previous points, creation is necessary for us to understand, and later rightly give glory to God through. The church is therefore the perfect body which have made known to us ways of reacting to Gods glory, and responding to it by given him the glory He deserves. Icon, Saints and relics are therefore, as the handkerchiefs and aprons of Paul, ways through which glory is seen, and glory is given, all to the glory of God the Father. What glory could we really give to God for the gospel and his mercy, if he would not become a human himself?
Please forgive me if I didn´t explain things that good. My english is not perfect, but I hope it gave an insight to the view that the Orthodox church holds to, and what every Christian ultimately needs to hold to.
Pray for me and forgive me.