2. Assuming you want to go every lecture lol:
First year, your timetable will most likely have 5 days a week.
Second year, you MAY have to go 5 days a week (if you do a particular double degree, for example) but most likely you'll go 4 days.
Third year, I think the actuarial component is only 3 days. Depending on your double degree or other subjects it may increase (eg I have 4 days this upcoming semester, but had 3 last semester).
3. Your hours are probably worst in the first year. First year 2nd sem you have something like 16 hours of lecture time (generally you have more like 12, give or take), which should answer your question lol