[Scrum] Non-Throwing Scrum half

[Arabcheif]

I guess I've got 3 questions here.

I'm thinking back to the days where you could drive from the 5m line for a pushover try.

When everyone and their gran joined the scrum in order to get it over the line.
Question 1 - Is this still permitted?
Question 2 - if it is, can the non throwing team's back line also join in.
Question 3 - Can the non-throwing scrum half bind to a lock/back row and help try to push the scrum forward (from his perspective)?

Hope Q3 is clear enough in my meaning lol.

 

[Camquin]

No - only eight in a scrum - apart from the scrum half everyone else must be 5m back.
So at a 5m scrum defenders cannot come into field of play - must stay in goal.
But once ithe ball is on or over the goal line it is not a scrum - but by then it is too late.

 

[Arabcheif]

This is what I was expecting tbh. It looks right to coin phrase.