Disassemble pentax k200d

Press the Fn button to bring up the Fn menu. Press up on the four-way controller to bring up the [Drive Mode] screen. Use left/right to select the one-handed clock. Press down, then use left/right to select the one-handed clock (the one WITHOUT the 2s caption). Press OK. Start the self-timer by fully pressing the shutter release button

It's all on page 117-118 of the manual you can download at
http://www.pentaximaging.com/files/product/k200dE.pdf

The battery charge indicator is temperature sensitive. If you switch off and on again, do you still get the low battery warning? Have you tried with a second set of batteries - either rechargeable, or lithium or alkaline. I would do this in a warm room, and try it with new alkaline cells. You lose some of the functions, but if the indicator say charged, and you can take a shot, then the body is OK.
Call me old-fashioned, but I use a multimeter on all NEW batteries to make sure they are functional - I bought a card of cheap LR44s and the first three were either dead or low on voltage.

I have the same camera and to my knowledge, a 'live' view with the LCD screen is not a feature with this camera. All pictures are taken through the eyepiece and then reviewed on the LCD screen. BC

Pentax K200D is a SLR Digital Camera..... in SLR you can the images in LCD after it has been taken.... while cliking image you need to use the Viewfinder......

That is the proper function upon start up, you can disable this in the menu settings.

My husband spent 1/2 hour interpreting the manual and found I had taken the aperture setting off automatic!

If it's a DSLR the picture most likely can't be displayed on the LCD screen (because it's an SLR) - I think the newest ones do this now, but older ones (even a year or two older) don't.

On a DSLR such as the Pentax K200d, which I have, if you want to see what your picture will look like before you take it, you could use the picture preview function. There is a ring around the button you push to take the picture - turn the ring clockwise slightly and it will take a preview picture.

Hope this helps!

changed the auto aperture under custom settings to permit and that was it

This can also happen when the lens have an aperture adjustment ring, and it is not set to the "Auto" setting ("A", on my Sigma)/

Depending on which series (screwmount, K, M, etc) you have, you'll get different levels of functionality, but yes -- all Pentax lenses for 35mm and DSLR (except for the medium-format digitals) will work with your K200D. Read the manual.