Grammar or Pronunciation ?

You should be okay if only one or two words are pronounced incorrectly. Be aware that most native English speakers can detect an accent in other people's speech patterns and compensate. However, if you're words are thickly accented and not pronounced correctly, some people will misunderstand you. Good luck and keep practicing.

I think that pronunciation is significantly more important than grammar in the sense that natives will probably still understand you if you're grammatically incorrect.

Consider the following sentences:

"I goed to the store."

"I went to the star."

In the first sentence, the tense of the verb is incorrect, but it's still understandable. In the second sentence, the last word is pronounced incorrectly and would cause some confusion.

Even though their both critical elements to the language, I think that pronunciation is more important if you can it least know the words and not the proper order.

Like you can say

Where train station ? Even though the proper grammar would be where is the train station?

They can it least interpret from the words you say of what you're trying to get across if you pronounce the words right.

English natives will understand you. I find that as regards pronunciation, it's not mispronouncing as such that can be a problem -- it's when a non-native speaker puts the stress on the "wrong" syllable that can render a phrase baffling.

We use language to communicate with others. Make sure that the other person understands you the way want to be understood.