Apis mellifera - european honey bees are very problematic here, though Vietnam is having great success with them.
most places it is not really economically feasible to plant honey flora as a primary crop.
rather, you locate your apiary near a floral resource.
sugar palms, coconuts, and rubber are all good local resources but insufficient for year round static production.
you have to migrate your bees if that is your principal activity.
mixed forest edge with regrowth near a plantation is your best bet for bees,

EO production on the other hand can rely on public trees, lemon grass, and many other cultivated botanicals.
i would not advocate planting eucalypts on good land as they poison the soil.
great along roads and on no mans land on stony ridges etc. make good posts and charcoal.
hell on tools for timber, hard and enduring.
the various acacias ( wattles for you aussies) are worth planting on the verges for timber.

see the teak trees flowering everywhere now?
that makes saw logs in just 15 years.
sorry for drifting off topic.

you can distill EO for less than $500 setup cost here. booze too. quite a large capacity set up for that price. they sell distilling gear ( large) in every town and it is cheap.

Username Taken wrote:Would 2 hectares be enough to make loy out of bees/honey and oil?

You don't need any land at all for beekeeping. Bees will travel many miles to the trees or the source of the nectar. Commercial bee keeper will transport hives hundreds of miles to areas where there are suitable trees, but the best money is in commercial pollination of flowers in orchards like peaches, plums, nectarines etc. It will take years before anything like that happens in Cambodia.

i really love beekeeping, one of the most productive and fun activities i ever engaged in.
distilling, both alcohol and EO's.
dairying too- the productivity of these things is just astonishing
provided you dont need to do it for money
farming is very rewarding if money is removed from the equation

First a question: does EO mean eucalyptus oil?
Second, I don't keep bees but there are plenty of wild bee hives in older mango trees in my yard. Now, Frank stated, "sugar palms, coconuts, and rubber are all good local resources but insufficient for year round static production." So my second question is, where do wild bees get their pollen from when the plants you mentioned are not in flower?

EO is essential oil.
Pollen and nectar are not always present in the same plant and both are needed.

You need very diverse plants all year for bees to thrive, so having native forest- even regrowth, near your bees along with a major " main crop" resource is a must. You will probably have to move them a few times each year anyway.

They can easily starve.
The 3 native honeybee species, are not very amenable to management.