Hi all. My NonB visa for employment was approved more quickly than I had anticipated. Am I correct in thinking I can change my flight to be sooner, or does it need to match the date I initially submitted on my evisa application? Thank you.

I'm on a 30 day arrival the runs out on 16 Feb. Im going to Nepal for a couple of weeks and returning for a few days before a trip to vietnam. I'd rather fly ou the 18th but can do the 16th. Does a 2 day overstay look bad in the future? What should I do here? Extend for 30 and only use 2 days? Fly out the 16th? Or just show up on the 18th because future immigration officers won't mind a 2 day overstay?