The Romans honoured their gods by performing rites specific to each god(dess). These rites involved giving offerings (sacrifices) to the gods. Many of these offerings were blood sacrifices, (slaughter of animals). Some sacrifices were offerings of flowers, milk, honey and the like.

No. Those who offered the sacrifices set fire to the offerings.

They made offerings and sacrifices, even in their tombs.

They are difficult to count, because there were various sin offerings, goodwill offerings, peace offerings, all of which were individual offereings, added on top of the regular daily offerings.

Temples