Getting really bogged down with this one..
Ham and eggs sustain royal court (7) - ??E?A?T I think it might STEWART but can't parse any of it.
Style of underpants in Action Man involved crazy consumer warning (3,7,4) - ??? ???T?I? ??T?
Weapon old Asian boss keeps close to chest (7) - ??S???N (The 'S' assumes 'Stewart' is correct)