Do Karaites sacrifice the Paschal lamb on Mount Gerizim every year?
No. That is the Samaritans, not the Karaites. The Samaritans believe in the holiness of Mt. Gerizim while Karaites believe in the holiness of Jerusalem. The Samaritans believe only in the Torah while the Karaites believe in the entire Hebrew Scriptures (Tanakh). The Samaritan Torah has minor differences from the Jewish Torah. Karaites accept the same Torah as all other Jews and in fact it was Karaites scribes who preserved the Torah used today by all Jews. The Samaritans bring the Passover sacrifice on Mt. Gerizim every year while Karaites do not currently bring sacrifices, because we do not have the ashes of the Red Heifer to purify ourselves (it is a great sin to bring a sacrifice while ritually impure).