1. Some ideas still seem to be a long way off.

2. Some ideas still seem to be far off.

3. The town is a long way off.
4. The town is far off.
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Can we use 'far' instead of 'a long way'?
What other expressions can we use instead of 'a long way'?

In these sentences, the two phrases are fine. I'm not sure they are always interchangeable, though. It would depend on the sentences.