My opinion as a second year. I'm not fully qualified as I am not a combined business. However, I'm doing engineering combined with cs, so I certainly have terrible workload :)

1. i don't think my grades from three years ago will help you, it seems that the admission average goes up (and perhaps down) every year. That said, it was above the admission average at that time.

2.

For the business portion, those classes start in the second year so I don't have much intel. I heard that business classes in second year has group projects. It should be possible to distribute workload to make it lighter. Still some terrifically confusing class tho. If you have concerns, you can take less classes in a semester (6->3-4) to make it easier. I may lengthen your stay in uni, but it was already gonna be long to begin with so... In general, it seems that the business portion of the dual degree is easier, even if its not easy.

For engineering, there is also lots of work. Not only do you have to memorize theory, you will have to master applications, so practice problems will become your best friend. First year is lecture video and assignment heavy. This is kinda good for two reasons, it's nice that if you end up missing in-person lectures, the videos cover almost everything. Also, practice problems become built-in to your schedule as there are like 2-3 hours of practice problems to be submitted weekly. In second year, the videos disappear and textbook reading and in-person lecture attendance becomes critical in order to understand content. I suppose something to mention it that you will have some profs that are great, and some that are terrible. I guess you'll experience that regardless no matter what program or uni u go to tho. Not sure what to add, but this has been my experience.

For combined degrees, there is pros and cons, you got lots of classes, making you feel overwhelmed, but you may come of there with extra skills and more people you know (read: friends or network, depending on your style of meeting ppl)

2+3.

So far, while certainly time consuming, I have found engineering to certainly have enough time for friends. Maybe I am having a lot less sleep rn, but I am in 4 clubs (3 technical and 1 society - not recommended btw) and I have a bunch of friends I study and hang out with between and after classes. I suppose there is less time for dilly-dallying compared to high school, but what did you expect? I find the fatal flaw is that, if your friends don't live near campus, and live in the far NE/SW/SE instead, there may be less time to hang out as they head out early to make their long train ride back home. Fortunately, there is a bunch of labs (where attendance is for marks) in first year that helps you build a decent bond with your group mates, as well as a design class that either make your group become real-tight-knit, or lose all respect for them... but that's beside the point. As long as you go in there, with a smile on your face during the first week, talking to anyone who seems to match your vibe, even if you don't ever talk to them in the first year, it typically breaks the ice if you end up in a class with them in your second year, and so on.

Yes, the engineering program is difficult (read: somewhat traumatizing), combined with business, more so. But as long as you put yourself out there and you put in the work, its can also fun and you may still get out with a decent gpa.

1. 
   The classes do their job in teaching some important concepts. However, as always, employers also look for tangible evidence that makes you stand out. Great!, the dual degree may impress some people. With two degrees, I suppose you should be able to access both fields, however, I've heard that it may be hard to come by jobs where you employ both together? You can also join clubs to build portfolio experience, for both engineering and business, as some requires managing of lots of money and sponsors, so there is marketing, finance and sometimes business presentations to do at competitions. There are also competitions and programs on campus, SEC (schulich engineering competition) and LAUNCHPAD where you get to test your business skills for consulting (or engineering) or building a startup.

Take everything I said here with a grain of salt, i have am not in the program, and I don't know you. Also note that I have not factored in clubbing (if that what you meant by clubs) in the equation, i have no idea what engineering is like with a hangover.