Hoping to get info/opinions on the feasibility of supporting myself as an English teacher in Poland.
Basically, that boat has sailed. You're about fifteen years too late. The accession of Poland into the EU, the economic crisis, an increasing number of qualified Polish English teachers, and scads of unemployed and unemployable British and Irish slackers who will teach for peanuts have all driven wages down, increased competition, and contributed to making teaching English for non-EU not a very attractive option, especially in the big, popular cities like Wrocław, Kraków and Warsaw.
Few schools are willing to go through the hassle of getting work permission for a non-EU citizen, and fewer and fewer offer full-time work contracts, opting instead for freelance "garbage contracts", which are useless for establishing residency. The profitable contracts with companies to teach employees on the job have also largely dried up due to the economic crisis. A few opportunities might be found off the beaten track in the hinterlands, but it's probably not worth the time and effort to seek them out as those jobs will become less attractive in the coming years.
Furthermore, wages have stagnated or gone down over the last few years, while the cost of living has gone up considerably, so even as a slacking-off, slumming-it year or two adventurous break from real life, it's not at all attractive anymore, and you might well end up spending more than you make, especially if you calculate in airfare to Poland and back and the cost of getting a residence permit. Setting yourself up as a freelance operator is not really an attractive option for non-EU citizens. You'll need a real work contract to establish residency, and those are getting very hard to come by.
Like InWrocław said, there are plenty of threads about this on this forum.
Is there anything I can do in australia, other than learn polish, that will look good on my CV?
It would be absurd to beef up your CV in order to get a measly job as an English teacher in Poland. Beef it up so that you can get a better real job at home. Under the best circumstances, it will take you over two years to learn Polish well enough to communicate relatively easily, and probably longer. It's highly unlikely that you will spend that long in Poland before giving it up, so there's no point in learning Polish.