mit der Tür ins Haus fallen — to fall into the house with the door. The Duden defines it as bringing up one’s concern without detours, too abruptly.
ohne Umschweife — without detours.
Lange Rede, kurzer Sinn — long speech, short meaning. It is said before a summary.
In der Kürze liegt die Würze. — The spice is in the brevity.
kurz und bündig — short and tied in a bundle: brief and to the point.
The Duden puts one word in brackets in its definition of the first idiom: [allzu] unvermittelt, [too] abruptly. The language also has a limit for getting to the point.