This is Rashi's sillyness. The first words in the Hebrew bible are:
בְּרֵאשִׁית, בָּרָא אֱלֹהִים, אֵת הַשָּׁמַיִם, וְאֵת הָאָרֶץ.
Rashi said that you should relable the vowels on "Barah" and make it "Bro", so that it reads (sort of) like "In the beginning of God's creating the sky and the Earth..." This interpretation is incredibly stretched, you just don't say it that way in Hebrew. It helps to be a native speaker of modern Hebrew tremendously with this.
The correct interpretation as simple past tense "First, God created the skies and the Earth..." is absolutely correct. There can be no argument. The construction "Bro" does not exist except in Rashi's head (although, I have to hand it to him, it sounds convincing and natural to a Hebrew speaker, for about 10 seconds. Bara is the obvious reading, and Bro would have gotten a vav if it existed, and most likely would have been something else, like --- Bereshit Briat Elohim et ha-shamaiim..., which is how you say it).
Still, as far as the ex-nihilo business, it isn't clear. The creation seems to be ex-nihilo, but it could also mean that this is the section-header, this is the creation story, and the tohu-wa-vohu of the next verse was already there.
On Biblical tense
Hebrew has tenses like every other language. I don't know why anyone would say otherwise. It's an absurd thing to say. I read most of the Bible fluently, and understand all its tenses intuitively, without any special training, aside from being a native Hebrew speaker. It is artful, but not strange.
The only unnatural tense thing about the Bible is that sometimes the past tense is used while placing the perspective in a future time (like: and you told your slave "go away" --- meaning, placing your perspective in the future, you will have told your slave "go away"), and sometimes the future tense is used to refer to actions as they unfold, to place you "in the action". These sorts of displacement of perspective are easy to read for a fluent Hebrew speaker, and its totally natural, and can be reproduced in English. It's sort of like:
Pooh was a bear. And Pooh walks to the forest. And when Pooh will arrive at the forest, he will meet Tigger. And Tigger was a tiger. And when Tigger and Pooh will see the fountain, they will jump inside. And they will leave the fountain, and go to the edge of the forest, and they will talk at great length.
And as you see Pharaoh, and you said to him "Come here and wipe my nose", and he wiped your nose as you said. And you said to him "Do it again", and he did.
The tense business is easy to keep in a good translation--- you just do stuff like I did above, and make the reader shift the tense perspective. When I translate, I try to maintain the proper tense.
I think fluency in modern Hebrew is essential for good translation. Without it, you are tone-deaf to nuances of meaning that only come with intimate familiarity with the roots and their variations. The tense thing is not a big deal, and not much different from other artsy writing in other languages.
EDIT: Why does "Bro" fool so many people?
Although "Bro" is a pure fabrication, it sounds really convincing, so that Rashi is a very good coiner of Hebrew. I had to sit and think about "Bro" for a significant amount of time, unlike other Hebrew misreadings, because it sounds just like a way of saying "In the beginning of God's creating", and I didn't know why, because I had never heard the word "Bro" before.
I figured it out. The construction is parallel to another existing Hebrew construction which is irregular, the construction "Ba" to "Bo". If you say "Hu ba", it means "He is coming". If you say "Be-bo-hu", it means "in his coming". It's not something that repeats with other verbs. If you say "Hu kana" (he bought), "Be-kni-ato" is "In his buying", and "Kno" doesn't mean anything at all. and if you say "Hu bara", "Be-briato" is the correct "In his creating".
But the irregular construction leaves a little bit of psychological resonance for the transformation "Bara" to "Bro", because it rhymes with "Ba" to "Bo", and "Bara" is different only in one letter. It is still wrong, because irregular constructions are irregular constructions, and they don't make regular constructions irregular. But it's convincing, like saying "She cleaned her pori" instead of "She cleaned her pores", it is a little convincing because of the pull of "tori".
But this is the reason it sounds so persuasive. Rashi knew his Hebrew.