Actually, there is a lot in your "sola scripture" that suggests Arius was right. Jesus certainly says that he and the Father are one, but he never says they are equal. To the contrary! It is Jesus who is sent, it is he who is to do the will of the Father, it is he who is lesser than the Father, it is he who calls the Father his God, it is he who says only the Father knows the day of his return, etc.
Reading St. Paul doesn't help either. It is Paul who says there is but one God, the Father, and that it was this God the Father who raised Jesus. Not much equality there, is there?
And it was precisely the same Paul who, in Colossians 1:15 states that Christ is merely "an icon (image) of the invisible God, the firstborn of all creatures." At no time does Paul ever say Jesus is God. Paul calls "God" only the Father.
None of the disciples ever prayed to Jesus, but they—including Jesus—prayed to God.
So, one can see very easily where Arius, who was no dummy, and certainly a prominent Church personality, not a stranger to scripture, might have gotten his ideas.
That guy had the same problem many people do...And it's not that he didn't understand what the scriptures said, he just chose not to believe it...
To say something like this, to place Arius on the same level is to tell the whole world you know nothing about him. Just because the Church disagreed with him, and even condemned him, doesn't mean he was a theological pushover. The same can be said of Tertullian (to whom you owe the term Trinity), or Orgien who, at one time, was the master theologian of such Church giants as +Gregory of Nyssa, and others. Yet, they strayed into heresy, not because they "chose" to as you suggest but because they put their private reading and comprehension above that of the entire Church. It is ultimately very narcissistic and vain, and prideful and as such a terrible sin to make yourself "smarter" than the combined wisdom of the whole Church.
Obviously, there is a lot more to understanding the sciptures then just reading them! Maybe one day the Protestants will realize that too, along with Mohammedans and and their LDS cousins.