Suppose I do the following:

1. Create a character as a pure caster other than Alchemist.
2. Learn at least one non-Alchemist spell, and raise Oratory to at least 1.
3. Change the character into an Alchemist.

Here are the questions I have:
1. Can the character cast spells while silenced?
2. In particular, can the character cast the non-Alchemist spell she knows while silenced?
3. Does Oratory have any function for this character?
4. Will Oratory improve by casting spells?
5. Are the answers to any of the questions above different in Wizardry 7 compared to 6?