Student or Learner
I wonder if there is a subtle difference in the meaning between "1" and "2".
1. The boss will kill me if I'm late.
2. The boss is going to kill me if I'm late.
Although there can be differences between use of the two that depend on context and situation, in the examples you posted and as the listener, I would not perceive a major difference. But in terms of a subtle difference, "...will kill me..." seems to me to be a bit more emphatic.
1. The boss will kill me if I am late.
2. The boss is going to kill me if I am late.
Is the tone of no.1 more certain than no.2?