People are missing the point about the 10K. The executor wants Nicole to sign a document agreeing to make this a 'gift' to her uncle and aunt.
Nicole is being unreasonable about a petty item like a €200 skip.
I don't believe the beneficiaries have any say in how the executor acts. That's the whole point of having executors, to carry out the wishes of the testator. But, the executor must act honestly and will have to account for every penny spent. With receipts.
Advice to Nicole, don't get bogged down in petty stuff like cleaning out a house. Ask permission to do so, if you think you're going to be unreasonable charge, so far a single skip is nothing. If you do go there, you might just be heading for a fight, so that perhaps ought to be avoided. There is no need to take this to war setting.
One other thing, the man's dead partner. Take consideration of that person's needs if you and your siblings can do so, particularly if you are getting a windfall and she needs a kind gesture of a small amount. One must move beyound antagonism for divorces and think about what your estranged father would have wanted.
Nicole can write a letter to the executor's solictors outlining her concerns. Putting things to paper will concentrate everybodies minds.