Hi! I’m not Lance, obviously, but I think I can help you with your questions, as Lance will no doubt do, too.
When Catholics worship God they are doing what was done throughout the history of God’s relationship with human beings. We offer a sacrifice. We read in Genesis that Abel offered an acceptable sacrifice to God, which was worship. Abraham offered acceptable sacrifice, which was worship. The descendants of Abraham offered acceptable sacrifices and the whole book of Leviticus is dedicated to the sacrifice established by Moses after the Exodus. The temple sacrifices continued on with only the Babylonian exile interrupting them into the time of Christ. Mary and Joseph offered an acceptable sacrifice as we read in the Gospels and Jesus established the sacrifice of his body and blood on Holy Thursday. We offer this one sacrifice of Christ on our altars at every Mass, and this is worship.
Prayer is not necessarily worship. It is when we offer sacrifice with it, but it isn’t when we merely ask for the intercession of the saints or for your intercession or anyone else’s. We don’t offer sacrifice to Mary or the saints. We only ask her aid and intercession, just as we would ask for aid and intercession from any other Christian or person of faith.
And we believe in the communion of saints because Jesus told us that those who have gone before us into heaven are not dead, but alive. Even the OT peoples’ souls were alive not dead. We know this because Moses and Elijah appeared with Jesus on the Mount of Transfiguration during which they discussed with him his upcoming death in Jerusalem. If their souls were dead or asleep they certainly wouldn’t have known anything about it, but they did. We believe that the members of the Church are divided in to the Church Triumphant (those in heaven and purgatory, which is a part of heaven) and the Church Militant (the Church on earth fighting the good fight of good over evil by spreading the Gospel). I hope that helps you.