Is it feasible/acceptable for me to convey my concerns to staff regarding performance of classmates on coursework reports? I am currently doing Physics undergrad at a first tier university. Due to my previous experience in Mathematics and slightly advanced age (five years my classmates' senior) I look at my classmates from a different perspective, and am honestly slightly disturbed.

Despite having received a class in LaTeX (with the express purpose of encouraging its usage) most students continue to use Word for reports (with sometimes shambolic results), most students neglect bibliographies, and I've witnessed students using only Wikipedia as a source, even when I pointed out that some of the information was inaccurate and referred them to a paper with correct information.

I've talked to one of the librarians, and he virtually pleaded for me to bring up such issues with the staff. Stating that he'd like to give a course on how to use the library, access online papers, write a report etc. to first years. Most students I've talked to were unaware they had free access to most scientific publications, and almost none seemed to have ever read a scientific paper.

I'm not quite sure what to do. On the one hand I feel it's not really my place, and I have other stuff to do, it's not my fault if other students are sub-par, and they are unlikely to go very far anyway.
However, in second year (approx half of students fail out after first year in physics), my partner in Experimental Physics performed so poorly I ended up doing almost everything myself in order to ensure my continued good grades.

I got special commendations from two of the three PhD students overseeing my three projects (the third didn't have the time to actually grade my report yet), though I personally feel my reports were simply on par.

Is it feasible, or even acceptable, for me to communicate concerns with staff, or to relay the request of the librarian with my own concerns added?
An undergraduate student is absolutely in no position to make any institutional changes in regards to the problems you've observed. In many cases, even the full professors have little ability to change the situation, due to departmental or administrative requirements for certain passing rates or median scores out of a class, etc. Possibly the faculty have seen this, and/or counseled concerned students about it, hundreds of times already. 

You should take some amount of confidence that this is evidence you're ready for your next big step (which seems well-timed, in that your Master's starts next year). You know how to properly research, cite, support, and use LaTeX to write a paper; and you will doubtlessly be using those skills in your next position. 

Frankly, the librarian was very much out of place to put the burden of responsibility for this on an undergraduate student. I call "foul" on that.