I am not sure what you mean by white blemishes on the bark. Perhaps you could send a photo for a better diagnosis. Rhododendrons have shallow roots and are generally easy to transplant if you remember to place at the same depth as before and not to plant too deep or cover with too much mulch. The white blemishes could be a mold from too much water or compost mulch around the stem of the shrub. Try not to wet the bark when you water and pull away any mulch from touching the trunk of the rhododendron. Give your newly transplanted rhododendron a good year to see if it settles in and sprouts healthy new growth in the spring. If not, then throw in the trowel. Life is too short to put up with ugly plants when there are so many other great plants just waiting to be adopted and added to your landscape. Keep growing, Marianne Binetti