Not aware of the information but NCAA Basketball is only really popular in the US. There is so little trading volume on exchanges and at Asian bookies that will take large limits on football many of them are like $100-$200 max on college hoops. It's no doubt huge in the US though but because the US market is the way it is, don't get see data such as how much matched at exchanges etc.
Re: second part.The limits at Pinnacle are $1,000 early and $3,000 late on point spreads - maybe more for big games, but that's the standard. Can bet the max multiple times when the line moves or limits reset.
Use this link click through several games mouse over odds at Pinnacle and see the movement. That happens automated. Small bets by joe shmoe probably don't move the line but at Pinnacle most large bets move the line regardless, more depending how profiled. With $50K bet however many times in $3K max increments it is going to move the line a ton. If the other side becomes +EV others will buy it until it reduces to a level no big bettors are interested in.