1. That is true about CPP. We are both the employer and employee so we pay both portions. You will always have to pay this but it's a good thing. EI is something you need to sign up for (if you're interested) and you have to pay into it for a year before being able to utilize it. I signed up for it in case I ever need/want mat leave or need disability/sick leave. I admit, I didn't really look into it too too much but for the amount I pay per year, it is worth it to me if I were to ever need it. My husband's aunt works for EI and strongly recommended I consider doing it.
2. I have never had to carry over anything so I have no advice
3. I lucked out and found a retired accountant who does it on the side now as extra money. She charges me $60 but is worth so much more to me! She is fantastic IMO. However, the first year I paid $250 when I got it done at HR Block and I believe $250-$300 is the norm around here (MB)
4. Really hard to say as each of our situations is so different. I have paid as much as $2400 to as low as $0 (besides CPP and EI). The goal is to get to $0 as close as possible and your accountant should help you to find ways to do this and give advice to the following year to increase your deductions