If I arrive at work before Fajr while fasting and can't pray due to a busy morning, can I perform my Fajr Qada prayer later with my Dhuhr and Asr prayers? Will my fast still be valid in that case?
Bismihi ta'āla
You would definitely have enough time in your busy morning, while being awake, to take a 2 minute break and fast. If your employer does not allow it, remove yoursel from this job.
It is a major sin to deliberately not pray, and all the blessings and positivity will be taken away and drained from you if you were to intentionally not pray and take it lightly.
And Allah knows best