in Rugby union the scrum half is the one who passes out of the back of the scrum and rucks and mauls. they can pass the ball very long distances and are usually quite small. to be honest i dont really know as i am a prop so this is a general description. feel free to change this answer(i'm sure you were going to anyway)
Fourie du Preez
practice, practice, practice
There is, however it is sometimes named halfback.
The three quarters are the wings and centres positions. This is connected then by the half backs who are the scrumhalf and flyhalf
No. 9 is the scrumhalf and this is the "quarterback" of rugby. He/She is the go between the forwards and the backs.
Whilst the term "spots the ball" does not appear in the phraseology of rugby I'm assuming that you mean a Scrumhalf
Halfback or scrumhalf is usually the smallest player on the field. Depending on certain skills, small players can be located anywhere in the back line
They are normally in the backs, frequently the outside half (1) and they will decide if teh ball is to run across the three quarters, kick for position or make the scrumhalf retail in amid the forwards to rumble the ball forward
Its not hook. Its hooker. The position is front row between the 2 props. Main role is to use their feet to hook the ball back when the scrumhalf places it in the scrum, (thats where the name hooker comes from) - In union the hooker also throws the ball into the line out.
Practice cathcing the high ball alot, dont be afraid to join in backs moves, work on postioning yourself right, help postition your wings, practice your tacital kicking i used to scrumhalf and flyhalf but got switched to fullback last season, i love it now
This is a difficult question as the response will be multi-national. Each country will have its own favorite from that era. In Wales the team were at their peak beating just about all comers. The most spoken about at that time was Scrumhalf for wales and Cardiff Gareth Edwards. Others will add their favorites to this post I hope.