1. At the outset, under the law of
England & Wales, a son or daughter has no automatic entitlement to a share under this father's will. There is merely an ability to apply to court under the 1975 Inheritance (Rights of Dependents) Act for a share in the will to be decided by the judge. So there is no guarantee that you will get any share at all. This application has to be founded on need and whatever grounds you can show that you are entitled to a share. I have never seen anyone succeed where they were given a sizeable legacy under the will.
2. Accordingly, you should certainly accept the legacy your father has given you in his will. The issue then arises is whether you would get any more if you made an application to court. Here if you provide some idea of the size of the estate, the number of other dependents, such as wife and family, I can assess whether you would in actual fact get any more if you were to renounce your rights under the will.
3. Sorry, I did not see that this is Scots law. Not England & Wales law. I will opt out and let someone else answer it.