From Goslate's developers:
Google has updated its translation service recently with a ticket mechanism to prevent simple crawler program like goslate from accessing. Though a more sophisticated crawler may still work technically, however it would have crossed the fine line between using the service and breaking the service. goslate will not be updated to break google’s ticket mechanism. Free lunch is over. Thanks for using.
So it seems that you won't be able to use their library to much effect anymore.
Concerning Sentiment analysis, there is a range of libraries that provide tools for sentiment analysis or its implementation ( senti_classifier, NLTK, Mallet, Weka...). There are also web services that provide these apis for a price (MonkeyLearn3.0 for example).
I am affiliated with none. :)