How can I expose the raster feature information? Looking to expose the band values.

You want to know a cell value of a specific point? PointOnRasterValueExtractor

You want to create vectors from all rastercells? RasterCellCoercer

I would like to know it for all cells. Looking to take a large number of raster images from an ESRI SDE and convert them to a geo-tiff however they are coming out black

I'm by no means a Rasterdata expert, but I think this has to do with the alpha band (transparency) being written to the GeoTIFF. Your solution depends on what you have and what you need, but if I guess correctly you can use the RasterBandSeparator and the tester to remove the alpha band and only write the databand (BAND0 in you screenshot) to the GeoTIFF.

Have you looked at the RasterPropertyExtractor and the RasterBandPropertyExtractor?