Flooring Tile - Granite Tiles in kitchen

I am planning on installing granite tiles in my kitchen floor. They will be 12" tiles. I've torn up vinyl tiles, ceramic tiles 1/4" ply wood and no the linoleum.

So I am at the pine flooring of the house. The kitchen is small about 10' X 12' the floor joists are 2x10's 16" O.C. on top of that is wood planks about 1/2"-3/4" on a diag (turn century subfloor) and then on top of that is T&G pine flooring. I was planning on installing either 1/4" or 1/2" hardibacker or wonderboard. Will I be ok?

I was reading about the flexural requirement of stone and was worried about what I've got? I've got about 1.5 or so inches of subflooring down but not sure if that is enough. I really don't want to raise the height of the kitchen floor too much. Im open to suggestions.

Over the diagonal wood planks you should have a 3/4" BC grade plywood, screwed into the planks, not the joists, at every 6" over the field of the plywood. Leave a 1/8" gap between the boards and fill with a cheap latex caulk. Then spread unmodified thinset with a 1/4" notch trowel, set in the 1/4" Hardibacker and set with galvanized roofing nails. Tape the Hardi seams as you go setting the tile using white modified thinset so the granite doesn't stain. Keep a 1/16" gap between the granite tiles and fill with unsanded grout.