Good choice....as Marc and others say, live view is a recent invention, and is no substitute for a photographers eye.
One thing you can do on the K200D is configure the on/off/preview button to stop down the lens for DOF preview.
BTW, as Marc keeps pointing out, switch it to centre weighted average metering - at least to see if your happier with the exposures (some complain about underexposure, but if you understand exposure its a snap).
And with your old 50mm f1.4, if it isn't auto aperture control, switch to manual exposure, set your aperture, tap the green button and your exposure is set.
All in all, the K200D is a great camera for the money.
As for the Oly E series - the sensor is smaller than the APS-C - and I'm not convinced its the way to go.
Anyhow, I'm sure you'll have a great time with your new toy.