أحسن الله إليك May Allah increase us in goodness and beneficial knowledge. In Rawatib prayers (specifically before and after dhuhr), is it blameworthy to read only Fatiha without a surah? And I mean in situations when one has less time such as at work or other circumstances. جزاك الله خيرًا

Reciting the second surah is a sunnah; therefore, the salah is valid. But I do not recommend that you develop this as a habit. The more uncaring you become about the salah, the more negligent you become about all of your prayers, whether obligatory or voluntary. This happens over time: if it doesn't happen this year, it can happen in five years. So, be keen on your salah rather than negligent.