I'm in Kin and absolutely love my program thus year, but definitely looking forward to 3rd and 4th year where I will have more choices into what Kin courses I am taking.
You're right, there are a lot of electives. You get 4 electives per year if you decide to take on a full course load. First year was quite easy for me tbh, but you have to remember, the study technique/style from Engineering to Kin is quite different. In Eng, where you do mostly physics/math practice problems, etc. Kin has a lot of memorization, understanding! (especially for first year in Anatomy/Physiology I and II.) and is basically all individual studying.
It's funny because since there are many other requirements for Med, PT, OT, osteo, naturopathic schools, the majority of Kin students end up taking the full year bios, chemistries, psychs, physics, and englishes are their electives! (Many of my friends joked that first year Kin courses felt like their electives and that their harder courses were chemistry, physics, biology, etc.)
--> Not to mention the required courses you have to take before graduating like Stats and Calculus.
2nd year was definitely harder and more challenging. I can guarantee you that. No degree is a flyby, and no degree let's you off easy. Second year sees much more weekly tests, more labs, more lab reports, more midterms, longer exams. Some courses are much harder than others. For instance, MSK Anatomy is pure memorization and understanding (I know people who have failed this twice) and Biomechanics, which is the physics of human movement.
Overall, if you really do want to switch into Kin, that is possible. (I'm not sure if it's too late now though, it's pretty hard to switch in unless you have 11+ gpa, as they only let in transfer students based on how many people dropped out of Kin that year)
I suggest looking at the course calendar descriptions to give you a sense of what kin courses and (much more interesting) upper kin courses look like. For instance, cardiopathology, neuromuscular exercise physiology, health psychology are examples of upper level courses.
Good luck!