And how many scrums ever even finish at the top level? Seems maybe one out of the five to ten that happen. The rest of the time the scrum collapses and the referee awards one side of the other a penalty. The way I see it, the team without the put-in doesn't want the scrum to finish, because all the forwards are in the scrum, not lined up across the pitch ready to tackle anyone with the ball. So, why not collapse, especially is the scrum is on the opposition's side of the halfway line, and hope the referee calls it on the side putting in the ball? Otherwise, a finished scrum could mean the ball gets out to the backs with only the opposing backs to beat to gain ground, or possibly score, with forwards running after play. Funny, it used to work that way with mauls and rucks, before defenders stopped contesting them!
Crooked feeds seem to be normal in the UK Premier matches that are now being televised in the USA. I don't believe I've seen one scrum half put the ball in between both hookers' feet in any game I've watched so far this September.
It's for BOTH teams! Neither team can have lineout participants jump before the ball leaves the thrower's hand(s). As a referee, I'd say about every other game I call this infraction. Usually it's on the very first lineout. If both teams do it simultaneously, and believe me it's happened, again usually on the very first lineout of the match, I warn both teams, and allow a do-over. I rarely see a second offence.
The law if very simple to understand: a player in the lineout can't jump before the ball leaves the thrower's hand(s). I call this when I see it, and believe me, it's only women's teams who don't complain. It's sad that it isn't called, but then again, who releases the ball immediately when tackled? Tackled players hang on to the ball as they roll once or twice over, twist or turn themselves around to face their own players while on the ground holding the ball while doing so. So, referees call some things, and let other things go. Nothing new there! I've watched a few of these premiership games from the UK recently on NBC Sports Channel here in the US (thankfully rugby on a regular basis can be seen on regular cable TV here, as it was in the late 90's on the now defunct International Channel!). Feeding the second row by the halfback in a scrum is criminally allowed by refs, but then again, in the last game I saw, Leicester v Bath, I believe one scrum was ever finished, as a penalty was called on all the others, usually for collapsing, and even on the one in which the ball was heeled out, a penalty was called because advantage was played until the flyhalf got tackled, and play whistled back for some infringement on the side of the scrum. The more I watch rugby, the more I wish the old laws came back: ban lifting, get rid of the referee calling cadence to set a scrum. Anyone can watch old games on YouTube and find out that when forwards went at it before this referee calling nonsense, there were few collapsed scrums. It's worse now with the referee getting to "set" the scrum!