Can the laptop handle more than 8GB RAM? The question has been asked before such as here and the short answer is YES: you can install up to 2*8GB RAM in this particular model.
Do you need more than 8GB RAM? Probably not, and that's just my experience: this model has a mildly fast i5 and a standard 5400 rpm HDD. If you want to spend more money on upgrades, get an SSD.
Can we install 8GB+2GB RAM? Yes we can, although ideally the 2 channels better have the same RAM installed. In other words, the laptop will perform better if you install 2*4GB instead of 8GB+0GB.
You have an empty slot and a 2GB RAM stick, should you install it? You can do that and test your laptop. If you experience any incompatibility issues (the laptop will freeze/act-out/not-start, etc.), you can take it back out.
Would I bother? No, if I had your current configuration, I wouldn't bother with those additional 2GB RAM, but that's just a personal opinion.