I just listened to the clips. I could understand your improvised speech better than your reading. When just speaking, you use different intonations depending on what you are saying (doubt, explanation, etc.) While reading, your tone is monotonous and it seems that the text you are reading is somewhat above your level: at certain points, you give the impression that you are fighting against the text.
As for your accent, it is not at all a problem to understand you when you speak, but I did feel it created some interference when you read.