Land held in Trust sold to related party

A Trust owns a piece of land

There are options to develop and sell, sell with planning or purchase by one of the trustees personally to sell on

I have a number of questions :-

1. Will the trust need to get a market rate valuation to sell to a related party - i.e trustees, or a company in which they are the sole directors and shareholders

2. Is the trust allowed to sell to a related party - or does this depend on the trust deed?

3. If the land is sold without planning, the related parties add planning and then sell at a big profit, will HMRC take a dim view?

4. Anything else we need to consider?

Any help / guidance gratefully received