I think it's very edifying to see you asking questions like this in a true spirit of humility, Amiga. It's a pleasure to share thoughts with you.
As for the songs you're into, I would say there's nothing wrong with them. They're cute songs. I know that sappy love lyrics can sometimes be considered quite secular but many words to famous opera arias and dittys are similar in tone. As long as there's nothing sɛҳuąƖ in the lyrics there's no problem.
I had to rethink my music collection a couple years back as it was somewhat hardcore and inappropriate. I figured it wasn't good when I wouldn't let my kid brothers listen to the stuff i was into. I was told in confession (because I asked) that i probably shouldn't be listening to all the hardcore stuff I liked so (begrudgingly, I admit) I started going through my stuff and taking out bits here and there.
I like what would be generally known as "classical" music more than most pop music anyways, I prefer going to a really good concert than a gig.
One thing I often wondered is how far music can have a physical effect on us. I used to be into a lot of industrial metal (and still love it, but don't buy it) and I think an investigation into the effect of it upon the emotions and the body could be interesting. Check out these kids at a Rammstein gig (I was going to go to one of theirs, but missed it due to exams) In retrospect i'm glad I didn't go, because I think the atmosphere seems a tad unsavory. Aside from the music (which most people will think is rubbish, anyways, and probably demonic, which I don't disagree with, so don't waste time telling me how rotten it is please anyone...) it's unsettling to see its effect on the crowd. All the horn-throwing etc. While the main singer guy is ridiculous and rather unintentionally funny, with his silly little nαzι goosestepping etc,the atmosphere nevertheless seems very unGodly. I think, for myself at least, that I could appreciate the beauty of music and God's gift of it in at the Proms, but most certainly not here. That, for me, is the deciding factor.
Edit: please don't follow on the links to watch any other of their vids. Some are quite disgusting. I chose this one as an example of how the music, while not accompanied by anything directly immoral, can project an impression of something unsavory nonetheless.