I'm struggling to finish in time, if I wasn't able to finish tasks 8 and 9 (which are the biggest, as far as I'm aware) in time to submit the project, how badly would I be penalised? Would I just not receive a mark for those or would I actively lose marks for tasks not completed? I'm going to try my hardest to get everything done before submission!

Please read the marking rubric. I must mark in accordance with the provided rubric. The rubric explicitly states what is required to receive each mark. UWA's assessment policy means I can't just take marks away because I feel like it (and nor should I). If you meet the requirements of the rubric you get the mark.