I’m a science one alumni as well and I agree that you should consider taking one or two English courses with it to keep your options open for honours. But I would not recommend taking more than 2 courses on top of science one in your first year as science one is very time consuming.
Science one although it will fulfill 4/7 of the breadth requirement you can easily take 2 more electives in 2nd - 4th year (you have your whole degree to fulfill the breadth requirements)
Getting into med school from my understanding has a lot of different aspects to it but I definitely do not believe that taking science one would be harmful to a med school application