From my research there is one more dimension to the word "ekklesia", and it's inferred in the passages you cite.
Ekklesia was a concept familiar to the first-century mind, especially in secular terms, as some of your references show.
At various times people were called out, or called together for a specific reason, or purpose. That is ekklesia, true enough.
But were they called out merely to listen to (or follow) someone? Were they merely spectators or providing an audience for someone else's show, someone else's display of authority? NO ! They were called together for the purpose of making decisions!
They were part and parcel of the decision-making process. Their full participation was assumed and regarded as indispensable. They were not mere appendages to the nucleus of the action. They WERE the action (humanly speaking). That is WHY they were called together - just like the Sanhedrin when they gathered to decide what to do with Jesus.
So, to correctly define ekklesia as a called-out people without pointing out it's intrinsic God-given authority, is akin to defining Parliament merely as a called out assembly who meet in Ottawa ... (and then what?) - without explaining the purpose for which they meet and the authority to see it through (with as much co-operation as possible).
The implication here is that the ekklesia is called out and vested with authority by God to make decisions in accordance with Jesus' prayer; namely that "Thy will be done in earth as it is in heaven ..." So the purpose of the ekklesia is to be active participants in bringing heaven to earth. That could mean various things such as singing His praises in this cursed world, practicing mutual love and submission in His Body, setting captives free, helping people in trouble, visiting the infirm, speaking truth in love, giving and receiving correction, invigorating and motivating other believers, learning together to recognize His leadings (like when the Holy Spirit separated Paul and Barnabas for a specific task), learning to deal with tensions, and a myriad of other things for which full participation in mutual submission is indispensable. I am not talking about "Kingdom theololgy", or "Dominion theology" which is a political fiasco. We're talking about being God's vessels used in a corporate way to make inroads in reversing the effects of the curse brought upon us by Adam's sin. We're talking about groupings of people who cluster together and respond in unison to an invisible Spirit just like schools of fish do when they all swish and turn AS ONE. They have learned to accurately respond to that spirit without bumping into each other and causing damage, which in our case is more difficult. With me(n) this is impossible, but with God ....
Thank you Jay! For far too long many Christians have been lead to believe that, if they are not on “the ministry team”, they are simply passive spectators when the church gathers. But nothing could be further from the truth! Each is to be an active participant. Hebrews 10:24,25 is often quoted as the basic reason why “Christians should go to church”, but I am firmly convinced that this passage rather outlines for us what is on God’s agenda for the normal assemblies of His people! It is all about “one anothering”!! “And let us consider one another to provoke unto love and to good works: Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.”
It is precisely for this reason that it is crucial for us, the Lord’s people, to evaluate whether our practices are simply derived from human traditions or are truly practices which are obedient to apostolic traditions received from the Lord, Himself! Are we building on sand or on the Rock?