Gary, welcome to the world of real cameras.
I don't use the K30, but one reviewer said it is the best camera Pentax has ever made. I do use the 55-300 however, and find my copy to be an excellent lens. I notice you are shooting at f6.3, which for this lens is nearly wide open (f5.6) at 300mm. As you probably know, long teles tend to be somewhat soft at their maximum focal length, so you might try shooting at f8 or f11, which should sharpen things up for you. I don't think this camera should be that noisy at ISO 640 so the graininess in the background could indicate indicates you may have done some sharpening in post processing - this lens should give you sharper images than these - have you engaged the image stabilization? You have gotten sharper pictures with "lesser" cameras at longer equivalent focal lengths, so you should be able to hold this one steady enough, so that is probably not the problem here, so you might also bump it up to 400 (which will allow you that extra stop or two), or use a de-noising program - If you use Photoshop Elements, I find the despeckle filter is more effective that the noise reduction filter which loses too much sharpness. Goos luck and keep experimenting - with your experience and demonstrated skill I am sure you will get the hang of it shortly.