Short answer: YES Both surfaces will need to be prepared. You will need to use a good quality construction adhesive that specifically mentions that it will bond to concrete and wood surfaces.
You can get this molding in individual 96" (8') pieces for ~$10.00/piece. Internet #205917000 Model # 0W623-93096 Store SKU #561342
I have seen some profiles that have a rounded corner piece but not at Home Depot. I personally don't like them though. I would make the corners with an extra piece and cut all pieces at 22.5'. This small piece will be about an inch wide and will lie tangent to the curved corner. I've seen this done and it looks pretty good. Much better than cutting 2 - 45' anglas making a 90' corner and filling in the void with spackle.
The molding is 100% solid southern pine. It is primed, so you will need to apply a finish coat of some kind.
Plan on lots of waste. If you buy two bundles, at least four boards will be damaged.
Depending on how tight the curve is, the composite model may work for you. Not sure of your experience with cutting trim but you could always make relief cuts in the back of the trim to make it bend. Royal Building Products 5523 29/64 in. x 3-1/4 in. x 8 ft. PVC Composite White Colonial Base Moulding Model# 0552308056
I would highly recommend using 2 to 21/2" 18 gauge nails with an air nailer. You can set them with a hammer, but one miss swing and your filling dents.
I am not going to be very helpful here. This is a very neutral flat white primer. The paint layer is very thin and while this molding arrived without chips dents or splits there were a lot of scuffs in the paint. It is likely sprayed in a continuous manufacturing line where it is likely to be very quick drying. just to handle the continuous process where it is cut to length after painting. Ultimately I am not likely to paint this baseboard, however it depends on how badly the caulking show up.