While it may be OK to convert the mosaic pattern to a herringbone pattern, you will have to have really well milled pieces to make this work. The mosaic pattern is very forgivable when installed in the pyramid fashion that most parquet is installed with, but the herringbone is another matter altogether.
Now that all said here is the basic instructions on how to start a herringbone floor.
Find the center point of the room, exactly. Lay two chalk lines at right angle to this center to both walls. Test this with the 3'-4'-5' triangle (remember the Pythagorean theory). You now have a large cross in the room, with it's intersection exactly in the center. Now snap another exactly 45 degree line through this center. Next snap another chalk line exactly half the width of the herringbone board below this diagonal line. Dry lay the boards (without adhesive) to get a good idea of how it's done. The first board is laid right on the line below the center diagonal and it's end (and middle) just touching the center spot. The second one is laid and right angles and on top of this, and so on for three row up. Now lay the boards to the left along the line. You ninth board should be along this same starting line. Go up the diagonal line until you have dry laid about 20 boards.
Then make a rough pencil line around these boards, remove them. And now spread the glue. You should be able to see the chalk line through the glue, once it has tacked off (follow Dri-Tac's excellent instructions). Relay the pieces in the same order. Allow the glue to set up on these 20 pieces for about an hour, then roll, then and wait anther hour until they cannot be moved out of place by hand. Now you can apply more adhesive in any direction you wish and continue, but try to fill most of the one quadrant of the room at a time. And be sure you don't spread too much glue so that it dries and won't accept the wood.
Sorry but if you find this rather daunting, you will find it more so if this wood is not perfectly milled. As the floor grows, your lines need to stay straight and true. So my best advice is to stick with the original mosaic pattern, and be sure to use the Dri-Tac glue at www.dritac.com. Other glues will fail with this oily wood.
As to sanding, have a pro sand this floor. And as to finishing, you will need to wash the wood with naphtha first to remove some oils, then apply 3 coats poly.