I see no problem when you want to learn the Latin grammar from Wheelock's Latin. But you'd better get a Latin dictionary. For example, in chapter 2, page 15, you can find a word basiat with a reference to basiare (to kiss). In the Latin-English dictionary of the book, there is only one related word basium (the kiss). So,
Lucia crucem basiat.
The author, Frederic M. Wheelock, did have some help from Catholic priests on his book, and there are several Christian passages in Loci Antiqui such as the Lord's Prayer from Vulgate, Matthew).
The only main difference is in the pronunciation whether you're talking classical Latin or ecclesical Latin. The latter is just like speaking Italian.
Good to know. I have Collins (Concise), which I hope will be sufficient. I think I may pick up Ecclesiastical pronunciation as well, if it helps with Italian. I know absolutely nothing of the latter, but my studies will require me to get proficient in French as well, so if I already know Latin, then I expect it would be very easy to pick up. My wife is very fond of Europe, and it would be nice to be able to converse more easily.
I did much the same with Hebrew (and I regret that I did not with Greek, although at some point I may take the time to remedy that). I made it a point to go with modern pronunciation to make communication today possible. So perhaps I was wrong when I said earlier that I would no concern for speaking it. You are all a wealth of information. Thanks again.