Your example is flawed because you're using the word record incorrectly. If you wanted to use record to mean storing a piece of information, your example sentence would be something like:
I have recorded the date of travel in the claim form.
You would never get a collision between the idiom and your sentence because in for the record, record is a noun, whereas in your example it should a verb and thus can't be used the same way.
If you wanted to refer to a physical record, the sentence would likely take a different form there too, something closer to:
I have included the date of travel in the claim form in the record.
With regards to your question regarding whether you should stay away from idioms and fixed phrases in sentences, it depends. If you establish enough context, it shouldn't matter. Let's take a phrase like on the ball.
He's on the ball.
Without context, I would assume the meaning of on the ball to be its idiomatic one. However, if you establish some context, you can make it a lot more clear.
I saw it bouncing before he fell. He's on the ball.
He got all his work in early. He's on the ball.
In both cases, the added context makes it a lot more clear which meaning is implied.
The more generic your idiom or phrase is the less worried I would be about it. If you're ever in doubt about the clarity of your message, don't use an idiomatic phrase. Plenty of ways to skin a cat, so to speak.