The Flash
Dennis Wilcock did 9/11
As for the off side, I'd tweak it and say no offside if one or more outfield players are in their own half. You don't want to encourage goal hangers and long balls hoofed up to them. So no offsides if any team is one the attack, generally.
Just the halfway line wouldn't prevent cherry pickers. You could cherry pick by just standing one step beyond the line and that's still a massive ground. You'd probably need to draw a different line on the pitch, maybe around 35-40 yards/meters.
Edit: Unless, I misunderstood what you're saying.