tiling a sunroom floor
I'd like to tile my sunroom floor. It is unheated and I live in Chicago, but I've monitored the temperature over the course of this winter and it doesn't seem to get below freezing. I still plan to use porcelain. I have a couple of questions that I would appreciate advice on:
1. Previously there was carpet with a pad underneath. I ripped it up and there are no cracks in the concrete, but it is scored. Do those lines need to be filled in? If so, what is the proper material?
2. There is a spot where the glue of the pad did not come up very well. Will that pose a problem for adhesion? If so, what kind of product can I use to get it up?
3. The sunroom is 10 x15. I was thinking of using 16 inch tile because it would mean fewer grout lines. Would the big tile look ok in the small space? What is the smallest grout line width I can use with this size tile?
My father and I did a tile floor together some years ago, but I am planning on tackling his on my own. So I'd really appreciate advice from tile experts out there.