No, it is not binding. I would absolutely accept it.
Virtus is specifically designed to provide support for engineering students so that they can succeed in this very challenging major.
There is no other living learning community specific to engineering students other than Flexus, the one for females. There will be engineering students in other living learning programs (like honors, scholars, civicus ,etc) but they are not designed with the singular focus of supporting engineers. Only flexus/virtus programs (both housed in same dorm, Easton) have on-site tutoring for engineering classes, block schedules to support study groups, career development for engineering and other bells and whistles all designed to retain students in engineering.
Here’s a thread I created several years ago that might be helpful http://talk.collegeconfidential.com/university-maryland-college-park/1455365-attn-engineers-special-living-learning-program-for-p1.html
Congrats on direct admission to engineering and Welcome to Terp Nation!