Like you, @sgcyclistsg, I also commute everyday to faculty and latter on to the supermarket to buy things for home. My doubt is if I can put some basket in a mountain bike without losing the agility it provides. What do you think?
How long is your commute? I'm assuming you aren't taking this bike to the trail? If you're concerned about handling, I think a rear rack + rack trunk/pannier would be less obtrusive.
I personally just carry a backpack to work. Laptops these days are very light + on days when I take public transport due to bad weather I bring more spare clothes so that I can travel light when I cycle.