Guys thanks very much for your comments.
You really help me understand that i an go on with my build as this is not a disaster.
Regards this straighten process i have some questions

Yesterday i borrow a dial indicator from a friend
Question 1
If i try to follow the straighten process as described here
Screw Shaft Straightness
and measure the TIR where should the node of the indicator touch ?
I am asking because if i put the node in the lower spot of the thread, as i turn the ball screw and have the indicator stable, the node of the indicator will pass from the lower spot to the higher spot of the thread( as the screw turns). I don’t know if i make my self clear.
Is ti logical to put the indicator node on the ballnut that has a cylindrical outer surface so i can capture the TIR.

Question 2
what is a logical distance for the V blocs

Question 3
How much pressure should i apply? I mean if i have a bend like that ) 1mm from the rotation center, i should apply a force to bend the the ballscrew to the opposite dimension so the screw take temporarily this shape (, and after i stop applying the opposite force the screw become straight | . This temporary opposite force is it logical to bend the screw 1mm ( temporarily ) or more? Again i don’t know if i make my self clear.

Anyway thanks for your patience.

Vagelis