The maintenance issues aside, and having engine probs in a Jabiru isn't unusual ,I get the feeling your not happy with the syllabus, it's been a while but I think it's standard to do the training you've mentioned after you've gone solo. It has a flow so your considered safe in the circuit , then before letting you go further afield there's a few things you need to learn.
I can remember being so sick of circuits and just wanted to get out there and fly around , but now, oddly , I really enjoy the time in the circuit getting acquainted with a new aircraft, experimenting with different landings and so on. You've asked some opinions, and it's a bit of a guess as to which school your talking about ,but if its the one I think it may be I'd be sticking with them , the CFI I'm thinking of is a good pilot and easy to talk to ( go to him with your concerns) . Another thing is your flying ultralights ,part of the trip is being ready for an engine failure at any moment , the 912rotax is such a good engine it can instill a fair bit of complacency ,you've obviously been taught well enough that a few issues haven't turned into anything major, my advice, have a talk to the CFI about it , you cam send me a private message if you want to talk , and just so you know I'm based at Coldstream and have no connections , other than knowing people in the area, to any of the schools around Melbourne ,
Cheers Matty