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You can search for that, there are threads.

You have to allow individual lens adjustments, so it's not a universal AF adjustment. Then there's a setting for lens adjustment in the menus, the manual is actually pretty good at describing this.

Wasabi batteries get a big thumbs-up from forum users. I've had another off-brand one, which was crap. The Wasabi seem good. You can always get an OEM one, but they're like twice as costly.

I thought there was a front setting and a back setting - two things. It seems to be the same setting + and -. That's what I meant. It seems to be implied that there was a setting for live view and a setting for VF focusing. As I mentioned I'd tested various +/- settings then I'd been doing necessary adjustments.
There's just the one adjustment (for each lens).

Some success! Got a new 55-300 lens which seems a lot better. I have some sharp images with this though it is difficult to hold it still.
DoF means some images don't have as much in focus as I'd like but the center is sharp now - when I hold it still enough.

I'm finding the images a little hit and miss as to whether they are sharp. It isn't always clear from the screen whether the shot is sharp or not. I guess I may get used to it but it does take a lot more effort than the cameras I'm used to. The results can be better of course. But anyway - things are looking up. The lens is working !

I'm still struggling with my K30 to get decent images. Most just don't look sharp. I'm down to the kit lens as the 55-300 zoom had an ingress of water and is away for repair.

Even with the 18-55 DA I'm struggling. I've thought that I may need the aperture settings higher to get more in focus, but things are still hit and miss. I thought a shutter speed of at least a 1/60th would be OK but maybe I need higher shutter rates? I don't know - I suspect this camera is faulty but I don't know what I should do as a test - what settings should offer a decent output. It frustrating as I have a Panasonic fz150 which is dead easy to use. The Pentax should produce better results but so far it's been a lot of disappointment.

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Higher shutter speeds are always good. So is stopping down, the kit zooms seem good around f8. Also, which focus mode are you using? It could be you're shifting a bit during the process of acquiring focus and snapping shots.

We'll all get disappointing results occasionally.

Try this, keep your shutter speed higher - 1/125 or quicker and turn off shake reduction.
Also try the two methods of LV on a tripod with timer using Av mode and static subject to really know if you're focusing correctly and if there's a difference in the hardware. Compare with handheld, fast speed.

Thanks for the tips. I'll try that