Thank you ! I noticed some dubious phrases :
"И если гвоздь к дому / Пригнать концом острым" > I understand "And would you just put the tip of a nail against a wall" (then it would self be planted, without needing a hammer)
"Скорей Нептун слезет / Со своего трона" > (God) Neptun would rather get off his throne (than you would make a move)
"Как на лету взглядом / Остановить птичку" > (It would be) like stopping a bird in flight at a glance
"И никакой силой / Тебя нельзя стронуть" > And by no power you can be moved
Anyway these are my guesses, and sorry for broken English.
(Edit) Oh and by the way, for "ветла" I found "willow".
Thanks for all the help! Wow, so many cryptic things here, especially that "Neptune" thingy. Thanks once again.