I would chime in for option C. I have a friend from high school (in her late twenties) who's teaching English in South Korea. It pays decently plus she has housing covered by her job. She's made a lot of headway into paying off student loans and has also had enough left over to travel extensively with (i.e multiple other continents). Pretty good option adventure-wise and financially. If you're looking to do something "meaningful" in a new location, I would also recommend options like Peace Corps or AmeriCorps. You can test out the waters in a non-profit area, if that's something you're interested in. It's exactly the opposite of a money-making endeavor, but you wouldn't go into debt as you'd get a stipend for basic expenses & can be eligible for an educational stipend later.
I'm the younger of two, but am still very financially conscious/responsible. I attribute that to my parents going through a lot of intense job stress during my middle school years. Despite their efforts to shelter me, I could sense how vulnerable they were and it's a tough thing as a kid to see your parents "broken down" by external aspects rather than magically being able to solve every problem. Made it tough to ask for money for new clothes/social activities when your parents are concerned about losing the house /supporting elderly relatives/working multiple jobs to keep things afloat. Rough years. I'm actually more "spendy" now (though still for experiences vs. for "things") since my parents' situation stabilized a while ago (& I think they're set for retirement). Plus, having my own funds from working (at least before med school) & not having much student loan debt while no longer worrying as much about my parents has allowed me less guilt about spending money for non-absolutely-essential things.
I had forgotten about getting a white elephant gift together until last minute (and wasn't near home), so ended up putting together what I thought was a decent gift from 7-11: "slumdog millionaire" dvd + portable corkscrew + ring pop. What I ended up getting: 3 homemade paper flowers that were rather unattractive (colored with marker on lined notebook paper) and promptly fell apart when I took them out of the plastic grocery store bag they were in. meh. I think some last minute gifts are better than others.
@maspan I do use the kitty system even if just traveling with one other person as long as there's still some shared costs. It doesn't have to require much upfront work. For instance, most wallets have either a pocket or a divider so you can easily separate your individual funds & the communal funds. To start of the communal funds, both people just contribute $20 USD or 1,000 baht or some other easy & common denomination. Say that's gone after multiple cabs, then everyone just pops in another bill. If there's anything left over, it's probably not going to be a huge amount, and it can go towards drinks or snacks or something else that everyone can share. It makes things so much easier than trying to remember who paid for what and dividing amounts to make sure things are even. If I'm traveling with a close friend, I don't really mind if amounts paid are not equal (i.e. if I overpay, I don't care). But equal splitting of costs is still usually what's aimed for and it's much less effort to achieve w/ communal funds in a kitty.
Sounds like a great trip! When traveling with friends, I've found it helpful to start a "kitty" of common funds to use for things like cabs / other shared costs. Pretty much, everyone would chip in an equal small amount of money at the beginning of the trip that would go into a designated coin purse. Anytime there was a cost that we would split equally (cabs, tickets to something we all attended, meals to be split, etc) we would pull from that fund. Much less mental calculation / memorizing of who bought what to think of! Btw, your description of the Koh Samui airport brought back some great memories. I'm typically a low budget traveler (i.e. will stay in hostel dorm beds), but I'm still glad I "splurged" for a direct flight from Koh Samui to Bangkok instead of going the budget route via Surat Thani / Air Asia. Instead of waking up at 4am to catch a ferry to catch a mini-bus to catch the flight at Surat Thani, I had a late night direct flight that let me spend a relaxing day at Koh Samui and then fly out of that beautiful airport (it seriously looks like a resort!).