Hi there,
Having just returned from Thailand I can tell you there is definatly no need of bolt plates there. all climbs
are bolted or slung.
As for chalk I took a bag still in original packaging and had no problems at all. I used heaps too so do
take spare. At climbing shop in Railay they sold loose chalk small bag 100 baht bigger bag 200 baht so
pretty cheap if you dont want to carry too much. No idea on the quality but the amount you use it really
wont matter.
Wish I was going back, you will have a ball. Stay safe