Many times I have done 16-19hour unplanned duties... in a disrupt this is to be expected and to have your duty extended is not uncommon for any airline so really growler your not telling anyone anything any airline these days wouldnt expect.
The only things that have limits on them is the amount of sectors you are legally able to operate, in nz we are allowed to pax one and then operate up to 5 domestic, or pax/operate one domestic and then operate 2 international.
EAA is not a bad company... yes the work is hard, and yes it will take a while for any sort of progression but if this is the job you want go for it. Opportunities that are full time and that do have eventual progression are hard to come by in aussie so i wish you all the best!