Me thinks you make to much of these layouts, positions, forms and what not.
The Lord said that where 2 or 3 are gathered together in His name that He is in their midst. That truth applies in a church building, or a barn. With ornate fixtures and sacred instruments for such services and without. Indoors and outdoors. God dwells not in temples made with hands, nor of rock or stone, but in us His people.
But who is His people. That is the question.
The Church buiding is the Gospel in architectural form, but yes, we (meaning us Orthodox) can worship without them. During Communism, many priests used to go into the forest with only an antimens (the cloth icon that contains relics and the permission of the bishop to gather as a parish on it) out into the woods, where the people would gather and Divine Liturgy was celebrated on the antimens laid on a wagon, etc. But for us who have means and freedom, there is no excuse for NOT having "these layouts, positions, forms and what not." My sons, as I mentioned, used to go with their mother to a well know mega-church, which is huge: my son compared it to a mall, with all the shops but no Cross. He noticed it was missing something. Our Orthodox parish is quite modest in size, but when I showed the antimens to my son, when it was spread out on the altar, he remarked "mama's church doesn't have half the things we do." Of course, with the antimens, the importance is that it shows that we have Apostolic succession, the living link to the NT Church, and with the Universal Church throughout the world.
Which brings up a comparison of two or three gathered in His name, and those CLAIMING to gather in His name: He who said "The person who listens to you listens to Me, and the person who rejects you rejects Me" also said “He who is not with Me is against Me; and he who does not gather with Me, scatters."
For instance, looking at the image that Handmaiden has graciously posted, there is the altar, the episcopal throne (in any Church, not only the cathedral, as any Church parish exists only by virtue of the bishop delegating a priest so it may gather), and the icons. Your two or three don't have these things, and I assume you claim that they shouldn't miss them. Needless to say, I, and more importantly, Christ's Church, disagrees with you.
The altar: a priest I know (actually he is rather well known) talked about going to talk to a congregational church in New England. He remarked that when he entered the "church" he noticed a small altar and a BIG pulpit, which told him all he needed to know about that parish. While talking about Orthodox worship, one of the parisioners asked him about incense, so he burned some. The minister said, in all the 300 year history of the parish, it was sure that it was the first time incense was offered in that church. Worship means sacrifice and offerings, the altar reminds us that Sunday is not about us, it's about Him. The ecclesiology of the two or three gathered in His name to request things seems to forget that, and "worship" means little more than a ad hoc meeting to present a wish list, along with sharing idiomatic "understandings" of Scripture.
The priest also noticed on entry that in the doorway all the names of the ministers from the 1600s were written on the walls of the narthex. That's still 1600 year short of the Apostles. The throne reminds us that we were received into the Church, we didn't make her up. We are gathered because we are the flock that has a shepherd appointed over it directly from the Good Shepherd. And being in union with the bishop, we are in union with all the other bishops in communion and their flocks across the world and through time, i.e. the One, Holy, CATHOLIC and APOSTOLIC Church.
And then there is the icons. Your two or three gather and decide what they think scripture is telling them. But without any bearings, they don't see their are reading their own projections into it. The icons show the Cloud of Witnesses who surrounded us.
Witnesses to us, because they have passed the Faith and demonstrated it to us.
Witnesses for us, because they intercede now before the Throne.
Witnesses against us, because if we decide to add or subtract the Faith delievered once and for all to these saints, who passed it on to us, the testimony that they have left in all the generations from c. 33 A.D. to the present will leave us without an excuse.l
So, yes, it is nice to think that you need only two or three to hang out a shingle to make a church, but it can, and usually is, very parochial.