a) Is there any source that mentions the need for one to have a סדר to learn about תפילה? b) Is it better to have a סדר learning about תפילה with a chavrusah or by one's self?
Since today we use siddurim with translations available, should one's primary focus be on translation of the words, the deeper meaning of the words, or both?
In answer to your fist question, R' Pinkus in the introduction to שערים בתפילה points out that you are spending, hopefully, at least an hour a day davening. If you do not appreciate what you are saying, you are wasting an hour every day. If you spend 15 minutes a day to understand what you are saying, you are really gaining 45 minutes a day. He therefore insists that it is necessary to have a סדר to learn about davening every day.
As far as the second question, the Magen Avraham writes that one should only have in mind when praying the simple meaning of the words (which I think corresponds to translation for those who don't think in Hebrew). If your learning is for the sake of improving your davening, then it would seem to be better to focus on the simple meaning of the words. (R' Pinkus, however, is stressing to understand the different modes and attitudes of davening, not just the simple meaning of the words. He asserts that your prayer will not be as effective if you do not understand what it is all about.)