I am new to modding skyrim, but have had a few years experience working with UDK, UNITY, C++, C#, java, and python each plus work translating from one language to another, so I can figure out most of what is written if you wish to go higher level. my key question here actually has to do with accessing a few key things for my mod (when completed will be released to community + steam)

is there any specific way to access when the player opens a merchant interaction (actually buying and selling, but before any transaction actually takes place)?

this should probably be self evident, but probably just skimmed to fast. is there a way to add a script to a object at runtime?

is there any way to intercept the OnSell(), or to get what was sold?