In September, I will be going to McMaster as a Life Science student.
I will be taking Biology 1M03/1A03, Psychology 1X03/1XX3, Chemistry 1A03/1AA3, Physics 1L03, and Math 1LS3.
I would like to get a master's degree in a field related to biology, chemistry, or psychology, ideally after getting an Honours Bachelor degree.

I have 6 units of electives, and I'm wondering if I should:

1) Be impractical, but take something that seems interesting i.e. Japanese 1Z06. However, it's 6 units and I won't have the option of taking another elective course. Also, when I learn a new language, I catch on relatively quickly to reading/writing, but pronunciation tends to be a problem.

2) Be practical, take Anthropology/Kinesiology/Writing and Informal Logic, a course (or two) that would benefit me academically because I would broaden my scientific knowledge, or help me with essay writing.

I'd appreciate it very much if you could offer me any advice.

Also, if I do not take Kinesiology, would I still be able to learn its course material in some other course? I don't want to fall behind in later years.

Interest = Practicallity

From personal experience:
Psych 1XX3 is a waste of a course (i personally dislike psych) if its not required for your second year major
If possible, take Physics 1B03 instead of 1L03. 1L03 is absolutely dumb and pointless.
If you're not majoring in a math intesive program, then Math 1LS3 is sufficient.
You don't actually NEED kinesiology material in other courses besides kinesiology courses.

As for your question, I don't think you should focus on one or the other. I think you could some courses you're interested in, as well as some courses that you think are more "practical".

But most courses that are "practical" will be the mandatory courses required for your program. There are no courses that are more helpful with your degree than those courses required for your degree.

As a personal opinion, I'd go with interest rather than practicallity.

There are lots of Biology courses which closely resemble Kin 1Y03/1YY3. Just to name a few, Biology 3U03, 3MM3, 3XL3.

You could always take Kin 1Y03/1YY3 in later years, but it's really hard to get into if you're not a first year