The Reno Stadium does have it's own house shot. It's a pattern they call Rhino and it's about like any other 40 ft top hat you would see anywhere else.
The Reno Stadium never has open play like a regular bowling alley does, but they hold a lot of tournaments. It's not just limited to the big ones either. Some PBA regional tournaments are held there of course, but there are a ton of small weekend tournaments. Pretty much anyone can use the stadium for your event just by contacting the city and finding a date. They have a linage rate just like any one else.
There is no league bowling, but some leagues hold their end of season sweeper at the stadium.
And yes, there are house balls under the seats and if you look behind the wall next to lane 1, there are racks of house shoes as well.