Buy something practical if you feel you are close to them, think wedding .....ironing desk, expresso maker or similar. If you are not that close flowers would be fine. ...I'm thinking flowers in a vase would make it something in between. Good luck.
I suggest throwing coins on the ground. I remember tossing coins upon entering a new home of friends/family for good luck, well wishes and prosperity. They must be picked up by the new home owner to avoid bad luck.
Absolutely. Housewarming presents are always welcome, in Poland as elsewhere.
Traditional such offerings might include, although by no means compulsory, a loaf of freshly home baked bread or a nice bottle of spirits; the former so that the new couple might never know want, the latter in order that the home should always know happiness and contentment:-)
