Sue, I'm not a native speaker but my parents were and I grew up hearing the language, and as I enter my senior years I am trying to learn and relearn what I should already know. I sing in English but seldom in Gaelic because I am not comfortable enough with my pronunciation. I live in Cape Breton where the language still lives among older folks but they are dying off and the Gaelic is in danger of dying off as well. However, there is renewed interest among learners and it is being taught in some schools. I think that you should sing Gaelic if you wish and encourage you to do so with a small bit of advice. Don't sing something phonetically that you don't understand the words for. If you understand the words you speak it will be much easier to add expression. I am not saying that you have to speak the language but just understand the words of the song. Sentence structure and idiom is much different in Gaelic so this may not be easy but it is a goal worthy of achieving. There is an amazing amount of Gaelic information and instruction available on line that you are perhaps already aware of. Mudcatter George Seto has a website with a lot of song information and he will no doubt respond to this thread as well.
Also I would add "correct style" is subjective and native speakers may have differing opinion on that as well.
Cum suas e! (keep it up!)
             Slainte,
                      Sandy