Should I be shooting trains in "Tv" mode??...Should whitebalance be kept at "AWB", I do keep it at "Sunny"...In very bright sunny conditions, is it to my advantage to have Oev at -1 more often than not??...What settings should I aim for in overcast conditions??
I have a habit of sharpening pics in PSP7 or Irfanview, should I be avoiding this??
Any advice is well taken, I want my photos to be of the highest quality. I never settle for "poor or no good", need to be number one. :)
I think moving out of Manual and into Shutter Priority (Tv) or Aperture Priority (Av) would be a solid base to start with seeing as you've only had 2 weeks experience with your camera. Which one you go for depends on what effects you want your image to have. If you want a motion blurred train or to stop the train in motion, then aim for Tv. On the otherhand if you want a shot of just the front cab of the train and make that a focal point, then use Av and select a wide aperture to only get a small part of the frame in focus and reduce your field depth.
Regarding sharpening, yes, you over-sharpen. A little amount shouldn't hurt, but there's a little too much here and if you look closely, you will find faint halos around objects. It's not that you should avoid it, just be less frugal when you apply it.
For your scene here, I would be recommending a CPL (circular polarising filter) so you get clearer colours, a more dramatic foreground and sky. This will also solve the over-exposure a little as it reduces light entering the camera by 1-2 stops. But a simple way around is to reduce the Ev in the camera. Whether it be -1 or -2 etc. will be down to you and what looks good. Weather conditions keep changing, so there's not exactly a set rule. Perhaps you used f16 to follow the 'sunny 16 rule', but this is only a rough guide when your camera is unable to meter - this shouldn't have been a problem given your equipment.
So there's no real hard and fast rule for sunny or overcast, but there are tricks to help get better photos in such conditions. If it's sunny, don't shoot into the sun otherwise everything will be backlit if you don't meter correctly. Backlighting is a good effect, but I assume you want to keep details of your trains, so perhaps this is one not to employ. In the end it's a case of knowing your camera and having a vision of what you want to capture, and then controlling your camera so that it does this. I don't think I can be of more help without being there with you when you take photos to show you through how to make the best of the lighting. Adaptability is the key.
White balance isn't an issue for me as I shoot RAW and JPEG when outdoors so I leave it on Auto and would adjust it later on in the post-processing stage if the camera got it wrong; the only exception is indoors, as you'll see below.
If pure JPEG, I have a grey card with me at all times so I can manually calibrate my white balance. Manually calibrating white balance is only genuinely useful indoors where lighting stays fairly uniform and it will reduce my post-processing workflow if I get the WB right in-camera; with outdoor lighting conditions, it keeps changing and you will need to recalibrate frequently.
Finally I can tell you want your photos to be of the highest quality and it's good to aim high. But start modestly and learn how to get the most from your camera before pushing on for that goal; I think this is your major hurdle, and spending more time taking photos and thinking about settings will put you in good stead towards great photography.