Translation of dechado

The script I am writing will shuffle the 1.5 million words and it will detect if too many words are from the same user. And if an entry is too long, I will skip it and rely on the sentences that we can hopefully make up together.
My correction were added and highlighted with yellow markers and attached to this email. Tell me now if you have any questions about grammar rules, since I was a teacher 10 years ago.
Today I have a lot of time because I've just returned from a 3 day vacation. For how long have you been teaching German? For about 3 years I have been studying Spanish mostly alone, with books and stuff.