This is a great question, and it gets at a number of important aspects in biblical studies. As you've already realized, the unvocalized form בראת can in fact be either the qal or the piel. The vocalized form in the Masoretic Text (whose best textual witness is dated to the 11th century) vocalized the verb to be a qal.
When approaching the text, we should ask, "Why does the Masoretic Text have the vocalization that it does? Would a different translation make sense or better sense?" Your suggestion for a translation does make sense, but would other readers agree? To check, let's look at some early translations (the best of which are actually older than our best copy of the Masoretic Text). That way, we can get a sense of what early readers of the text would have thought the word meant.
Greek: The Septuagint (which was well established by the 3rd century) has ἔκτισας (an aorist indicative verb that we can translate as "you created").
Latin: The vulgate translation (which we can date to the late 4th century) use the perfect indicative verbs constituisti ("you established") or creasti ("you created").
Syriac: If we look at the Syriac version (using the Ceriani's Peshitta, which is dated somewhere in the 6th or 7th century) we find ܒܪܝܬܐ, which is a Syriac verb of the same Semitic root as Hebrew verb, but without the connotations of cutting down.
From these versions (and there are definitely many others we could and should consult if we want to get a more comprehensive approach!), we see that the vocalization of the Masoretic Text is in line with the consensus reading. However, as a reader of the text, you should still ponder and argue for other reading if you think it's warranted. Yours might in fact be better! Hope this answer gets you to continue mulling over the sacred texts!
