Welcome to the community.
Is this an invasion from Canada, seems we've been getting quite a few members from our neighbors to the north.
With regards to your previous vehicle. I owned a Focus, Kona edition. While I wont say I loved it, it was a Ford after all and my first vehicle from them (my last as well), it never gave me any trouble outside the fuel pump which was a known issue.
I service a couple Focus vehicles as well, both SVT versions. Ford dropped the ball big time not pursuing that line particularly in light of the RS version that was available in Europe.
Anyway, with regards to your question a few of the things that come to mind are:
1. Supercharger coupler. Perhaps not a really common issue, but easy to fix
2. Lower Intake Manifold Gaskets (will leak coolant into the engine). If it has the older design plastic gaskets, then its likely to develop a leak at some point. A tad bit more involved than the coupler, but by no means overly difficult if you have any experience turning a wrench.
3. Valve cover gaskets. They will leak over time, but again not a terribly hard thing to take care of.
Thats about all I can think of at the moment. Every car line, without exception, is going to have its historical issues. The trick is comparing that with your mechanical ability and determining if its something you can deal with should the situation arise, or at the very least will it be something you can get help with from a local club.
