1) Blade is the word
BELGRADE without REG leaves BLADE. A blade could be described as "sharpish".
2) Down is a soft feather. Horses have hair so you should not be able to get "down" from a horse. ;-)
3) W-H-I-T-E
5) There are 24 blackbirds left. Twice 4 and 20 is 28 blackbirds so you shot and killed 4.
The 4th one has me stumped, though.