The first on is soft, so in reality will never make it into a frame on your wall! The key next time is finding a way of getting closer - a lot easier to say than do though. If you do consider the baiting route, then you'll be very lucky to get what you want fist time out - you'll be looking at turning it into a longer term project. Plenty of people on here do similar things, might be worth a PM or two.
Regarding the settings, you could have done with boosting the ISO a couple of stops - don't be afraid of upping it within reason, with ISO 800 you'd have got shutter speed of 1/800th and 2 stops of increased exposure on the bird which would have helped with everything bar the size of the crop. As already mentioned, it is too soft to realistically salvage, but in future this shot framed this way would have been better losing half the frame from between the bird and the left hand side, then cropping the rest to suit your taste. Save the close up's for when you can get more pixels on the actual subject.
Shot 2 is purely a case of you need to get closer
The last is heavily back lit, and you need to be very aware of the angle of the light before pulling the trigger. The brightness top right of the bird is the light coming through the feathers and will always be present to some degree with backlighting. You'd have needed to add in a fair bit of positive exposure compensation for this shot, and be careful the colours don't become all flat and washed out. A difficult shot to get right, but works very well when you pull it off correctly.
Similar to the kestral, you needed to have upped the ISO to get a faster shutter speed as there is movement in the bird, and again, this would have helped with your exposure.