1) Double. Lack of a 4th ♥ is a small flaw, but otherwise, hand is perfect for this action. I don't think much of waiting and perhaps acting later depending on how the acution develops. 2) Double. This hand is worse IMO than the previous one in spite of more HCP, but still, I have good support and I much prefer X to anything else by a good margin on this hand. Swap the Q of ♣ and the K of ♥ and I may overcall ♣ now. 3) Double. This of course depends on the partnership, but at your level, Edi, this is most likely for takeout :D Parner may be 4-3 in the majors for his 2-level X, and even at imps and vuln, I think I prefer this action to 4♦ which will certainly get you to the right suit, but too high IMO; the wasted Q ♦ argues for staying lower I think.