There are some interesting concepts as reported on this post, rucks and mauls. Had no time to play this weekend, so I keep on studying them. Anyway, finding a compromise between yours and the three different italian ones, is a complex task...

Nel giocare rugby di Subbuteo in Italia, sullo scrum, quando decidete che la sfera è fuori e può allora essere giocata. Fate uscire la sfera dalla parte posteriore dello scrum, o quando è dallo scrummer.

Inoltre avete limiti su quanto lontano la sfera può essere scossa da gioco aperto

Paul, the italian translation is quite complicate to understand, I hope my english is just a little bit better to comprehend...
Anyway, your first question is about the scrummer, isn't it? That is one of the debating points here. Somebody love it, somebody hate it. In Flavio Firmo rulebook you will not find the scrummer because its random output is not similar to the real rugby, where the team introducing the ball more often get it. Me and other guys here love the scrummer because it is so typical Subbuteo that you cannot play without it. Our compromise is that if the ball comes out from the scrummer tips the team introducing it get it, so it's 66% of chance. After that the ball is put behind the forwards, where is the scrum-half. We still have not "inside the scrum" play.
Even the second question is under the lights. Your rulebook (and Flavio Firmo one too) states the ball can be flicked no more than 2 inches away from the attacker. We think that to open a little bit the game the attacker can flick the ball further (the limit is still not clear, remember that we are just testing the game and many of the guys interested in the game never played Subbuteo Rugby before, or knows Rugby rules) but, we say, imagine that when the ball is flicked longer than 2 inches, the ball is not where the attacker is, but where the attacker will be after a sprint, so if the ball is flicked long (let's say no more than 4 inches) with the following flick the attacker must stay close to the ball (1-2 inch?) to keep the possession. This leads to other complications as usually the ball is the offside line. In this particular case we think the attacker should be the offside line, so every defender in front of the attacker, even if behind the ball, could try to tackle the ball carrier from a better position.
As I said you there are many differences between rulebooks. We at Old Subbuteo are looking to get a playable game even by people that are not rugby fans, but desire to play because is just Subbuteo, and at the same time a nice real Rugby simulation. Not an easy task, though...

On using the scrummer, there is a way that you can get the ball out for your teams on a 90% basis. If you hold the ball at the tip and place it .5cm in the top hole and pointing to your figures, then squeeze it hard, the ball shoots out fast, and if your figures are placed apart the ball goes a bit past the first figures.

Also look at the rule in the hybrid rules I sent you, about letting the attacker have 3 flicks then the defender 3 block flick, this gives the attacker the chance to move forward and the defender the chance to get his figures onside.

You can move the ball more than 2cms in any direction other 5cms directly in front, for example you can
hit diagonally for many more cms aslong it is not more than 5cms in front of the fihure that hit it last. Also you can say 'kicking' and hit it longer than the 5cms rule.