@The Pentacle Queen,
Of course it is possible to get better, not only at explaining your arguments and beliefs, but, even more importantly, being able to analyse them yourself and determine the logical and empirical flaws.
You have noticed yourself that you are already doing better at it.
If you can attract folk to your threads that don't just yell ar each other, A2k can be a great place to develop your abilities.
I don't know what you are studying, but it might also be possible to find fora specifically about the things you are studying, where you might find more people with expertise to discuss with, too.