They are all correct in the sense that there's nothing wrong with them grammatically and you will be perfectly understood by the natives. However, the 2nd and the 3rd sound like something that foreigners would say. The 1st one sounds more natural, I even propose if you drop "bicara" and just say "Saya bisa Bahasa Indonesia sedikit-sedikit", that definitely sounds like what natives would say. Now don't you worry about tenses in Indonesian, we don't have any. You want the equivalent of present continuous ? just add time indicator word "sedang" (currently) and boom...present continuous. Want past tense, add "kemarin" (yesterday) and boom..past tense. And don't mess yourself with complex tenses like future perfect continuous tense, eh..who need that, we Indonesian are too busy grilling satay and eating nasi goreng to bother with complex tenses

In my opinion, 2nd and 3rd sentence have same meaning. For the 1st one there's repetition, more like you present continues.