RE: How do I merge nodes is RAM Frame model?

There is no align braces command, they can't even be moved manually, so you have to delete and reenter them. When braces are added, they should snap to column intersections automatically. If you are manually modeling a chevron brace using add special method, be sure to measure to the apex from the same column for both braces. That prevents a round-off problem when the beam length is not easily divisible by two.
It always best to have the columns and beams adjusted first (including slopes) and then model the braces.