Thanks everyone!

I was worried how a stroller would go on the rough terrain. We have a hiker style backpack that we were thinking of taking, but the only problem is that he won't be able to sleep in that. I was thinking of getting a 2nd hand ergo or similar so at least if he fell asleep he'd be comfy. Although, I imagine he'd get pretty hot in an ergo.
We will be staying at the Dynasty and are going with some friends who go twice a year so they should know all the good places to eat. DS is pretty good with rice and noodles and spicy foods etc so hopefully he'll be fine.
I'm just a little worried as it's my first time overseas and I don't know what to expect!
Is the water safe to wash bottles/sippy cups in? Is there anything (apart from probiotics) I can give the kids to help prevent them getting sick?

Thanks for your advice. I'm sure I'll be right once we're there but for now it's a bit of a freakout!