Is Christianity a religion of peace? Has it always been so? What is Falwell saying without actually mouthing the words?
Yes.
Has it always been so?
You ask a rhetorical question, but will receive an honest answer: No; Christ's Words are not peaceful to those who would prefer to fight against Him. However, for those who submit themselves to His Truth, there is "peace that passeth understanding." Does this internal conflict mean He advocates violence? No, of course not.
Christians who do not follow Christ's two commands: "That you love the Father with all your heart and love your neighbor as yourself" are either in sin or commiting sin, as there is no violence in these commands. We are also to "go into all the world" and preach the Good News.
You will not find in the New Testament that Christ demands that Christians kill any one.
What is Falwell saying without actually mouthing the words?
What he's been saying for over a year now: Islam is NOT a religion of peace. It is an evil religion, founded by the Evil One; it is not from God above, but the devil below. It is a false religion.