I came from delhi... RNAC took charge of my luggage... and I find people in transit really good... It was RNAC from KTM to Delhi and there after British Airways. So, I say delhi is safe when from Ktm to US. In my case, i did not have to pick up the luggage so no hassle. I had spend 15 hrs night there in the transit and was really safe... With this experience delhi airport is good.