The second issue is any tool part
Any grip, any guard, any metal head.
You shouldn't run into a problem provided you don't throw (left click charge) or fling (turn+release rightclick) - oh, and also provided you don't actively try and push the item through objects (namely the floor and walls)
I can't claim whether this issue is scaled back or not, in some ways, it is seen as partially a feature, that is being a little overzealous to try and alleviate certain instances of "stuck"
The first issue should hopefully be addressed already. - It can be "alleviated" with saving and reloading (should despawn them, bringing the customer count back to default)
The MAIN cause but not swearing its the only cause of this, is shield customers. Completely avoid selling to shield customers at all for this version (0.1.0o) This should be considered "extended" to customers that ask for more than just a single weapon, too.
There's also a third issue you may eventually run into, that should also hopefully be fixed by the next patch
It deals with Specific Sword Requests, Customers that specify what guard, grip, and blade to use for their one hand sword, should either be avoided completely or.... Do not get their order wrong. If you get their order wrong, or rather, if you're holding Any item that isn't their correct order they will cause guards to spawn, quickly, in the shop causing lag and probable crash.
Again. your first issue and this should hopefully already be addressed.