Scenario 1: No,
Gimli's Helm blocks no wounds. You'd have to use the
Armor to block both. But If you did nothing, he would only take one wound because of the helm.
Scenario 2: Unless your using the Gimli Ring-bearer, You can't choose to wound him. But if you are using Gimli Rb, yes you can block it.
Archives of Minas Tirith is the forum for rules questions. Have a mod move it there.