For me rapid is plenty of time to think. If you reallly are after something play what you know 10-15 moves comfortably in that opening and make sure you know the middle game well. I play the Sicilian for rapid and now the Alekhine for black. White I play the London system and am toying with the Blackmere Diemer, London system and the QGD e6 Nf6 d5.
As black play the 3...Qa5 Scandinavian against 1 e4, and Tarrasch Defense setup against queenside openings (the London reversed can also be used at times).
As white Play the London against 1...d5, and the Trompowsky against 1...Nf6.
E4 E5