Questioning Catholicism

My sister points to this site, Catholic Questions - questions from Catholics and about Catholicism, and its questions that have gotten her confused. I'll try and sneak in my answers to the site's questions about Catholicism (from a Protestant perspective) and invite all who might wander in to chime in as you please. I'm not a trained Bible scholar nor a theologian, but I'll give it a go with what I have learned so far and what I find as I do some research. Please pray for me and my sister, and all whose faith is shaken by questions like these.