You'll have to contact the designer and ask how thick the walls are.
FUD is quite fragile at the minimum wall thickness of 0.3mm
But.. this model http://shpws.me/lDev has walls that are >2mm thick and I'd dare say it could support 15lbs without crushing
So the answer is mainly in finding out how thick the walls are.
Yes it can be painted.Patience, Persistance, Politeness - the 3Ps will help us get us to Perfect Printed Products