Sure, it definitely has an old-timey ring to it though. My (native-born American) grandfather used it quite a bit.
It has a connotation of a backpack used for storage or hiking, and it is still frequently used in the military. A frequent event in bootcamp is a "ruck march" where soldiers hike for many miles with a complete "kit" -- a full "rucksack".
For comparison, I would never call a student's bookbag a rucksack.
Dialect thing. People should get what you mean though. In general I think the distinction is that a "rucksack" is more likely to be a small, old fashoned, leather or canvas thing made for carrying hiking gear, whereas a "backpack" is what a student probably uses, unless they use a "bookbag" which is sometimes a backpack, but can also be a bag of pretty much any sort fit for carrying books.
Здесь and тут are virtually interchangeable outside set expressions ("тут" is considered more colloquial). They both mean "here" literally. "This place", I mean.
- AFAIK, they are always interchangeable in our course. I think we did not use any set expressions (except, maybe "тут и там") that require тут
- тут же is a very useful expression that means "straight away"
Вот is connected to the idea of pointing at the thing, showing it to a listener ("here is it, look"). Maybe even literally.
Has anyone seen the movie "Trading Places"?
In it, in one scene, Jamie Lee Curtis pretends to be a German tourist, all done up in long braids and lederhosen, and she refers several times to her "rooksack" (rucksack).
That's the first time I ever heard the term. But then, I've never been back-packing in Europe.