Elin,
re: "What about Rev 1:10?"
What is your point in asking that question?
I'll let you tackle that one.
re: "And there is the testimony that Christians met on the first day of the week for the Lord's Supper (Ac 20:7)."
Actually, as far as the Bible is concerned, there are only two times mentioned with regard to anybody getting together on the first (day) of the week - John 20:19 and Acts 20:7.
Does your Bible not have 1Co 16:2?
The Acts reference has them together most likely because Paul happened to be in town and he wanted to talk to them before he had to leave again.
Is that Scripture talking, or you talking?
The breaking of bread mentioned (even if it were referring to the Lord's Supper) had nothing to do with placing a special emphasis on the first (day) because Acts 2:46 says that they broke bread every day.
No, it doesn't.
They met in the Temple courts every day.
They broke bread in their homes, and it does not state how often they did it.
re: "There is also testimony they took up collections when they met on the first day of the week (1Co 16:2)."
There is nothing in that scripture that says anything about meeting together on the first day of the week. The text merely says that everyone should "lay by him in store" on the first day of the week.
Gee, wonder why the first day of the week is even mentioned then.
They could lay by store any day of the week.
Why Sunday?
Every Sunday they were to bring what they had set aside for the Lord's work, so it could be collected at the worship service, not at home.
Justin Martyr's
Apology, 1. 67-68, indicates that in his time (c. 150 AD) offerings were brought to the church on Sundays.
But don't let the evidence affect you.
re: "There is much Biblical evidence that the Lord's Day was the first day of the week in the NT."
I'm not aware of a single scripture that ever refers to the first day of the week as the "Lord's Day". What do you have in mind?
I have in mind three things:
1) correct hermeneutics that doesn't require a simple declarative English sentence to establish what the Scriptures mean;
2) for Scripture does not state: "God is sovereign," but it is nevertheless the testimony throughout Scripture (Da 4:35; Ro 9:16-19); and
3) your theology is driving the meaning of Scripture, instead of Scripture driving the meaning of your theology.