I would agree to change COMP1917 and ENGG1000 if you could get ELECXXXX. Both of the former can be done in 2nd semester. If you are only able to swap 1 of them, you should swap ENGG1000.
Yes, carry your student card at all times (Transport Officers may check) and may be required when purchasing tickets.
I'm predicting that 8am is not that bad but the afternoon is quite long at 4-6:30pm
It is easier to choose Software Engineering first then dropping to Computer Science compared to starting Computer Science and climbing to Software Engineering. You should decide on it before the end of your first semester because that is when they start a specalised course for Software...