Have the Royal Family ever had their benefits cut as they couldn't prove that they were actively seeking employment?

No, certainly not, they have never been unemployed. Have you never seen them wearing a uniform, smiling and waving? How dare you insinuate that that isn't work!

The Royals are paid for by the Crown Estates

They have never sought employment and continue to get above inflation pay rises year after year.

Effectively, yes. Decades ago the Queen and the UK Gov’t agreed to massively cut the funding to the UK Civil List which directly paid members of the UK Royal Family.

Following that, just the Queen, the Duke Of Edinburgh and The Queen Mother received Civil List payments and they ceased completely in 2011.

Profits from the UK Crown Estate and the Duchy of Cornwall now pay for the Queen, The Prince of Wales, and the Duke of Edinburgh. They in turn support dependent family members. Expenses incurred to carry out official Royal Visits are submitted against the taxes paid by the Royal Family.

So to a huge extent the UK Royal Family is effectively self-funded. They’re massively cheaper to run than any Presidency, and vastly less likely to be corrupt as they already have all they need.

Royals who get no money from the Queen (such as the Duke and Duchess of Kent) also carry out a large number of public engagements.

The Royal family are not and never have been on benefits. And they work a hell of a lot harder than you ever will troll.

No but they should have, none of them have had a real job.