You need to read at least the first 8 posts of this thread: New and Potential Owners START HERE!
...and "driving cautiously" as in "Avoiding accidents" has nothing to do with mechanical repairs, assuming you have insurance against accident damage.
If you mean "driving slow and babying the engine" then yes, you can expect to have lots of issues from carbon buildup. 200,000km is... 124k miles? It's maybe 50/50 that you can get the engine to that mileage without issue.
And no, it needs 91 octane + (US spec number, not sure if there is a Canadian conversion). If you can get it to run fine on anything less, it means the engine is losing compression. The lower the octane you can go, the worse your compression is.
Read the thread. My gut tells me that this is not the car for you. Maybe as a 2nd non-daily driver, but not your daily.