1)With increased luggage restrictions it may be cheaper to do several trips from the US -> Wherever you want to go. For example - get a RT ticket to Istambul, then a cheap flight to greece. Do the same to BKK & get a ticket to KTM. It will probably cost the same, or less, to do it this way and allow you more flexibility with changes. If you fly a non-US airline much more flexibility with changes (i.e. I've flown Singapore, China Airlines and EVA and been able to change the return date without paying anything on all of those)
2)Nepalese trekking isn't as cool as it was. i.e. the Annapurna circuit almost entirely paralells a road Research some of the alternate treks; getting maps/logistics can be much more of a pain in the ass
3) Other places - what do you want to do and what time of year are you going? The alps are awesome, so are the andes, so is SEAsia, Australia + NZ, Sri Lanka + India, Central Asia, China....
4) TAKE MORE TIME AND ENJOY YOURSELF!