I've not used the speaker's podium, but the manual states the hold a speech job shouldn't require anything. Are you sure your dwarves aren't busy doing other jobs?
As for golems, there is no way to do that. You can only put a golem in your military if you create it yourself, in which case you put the dwarf who will transform into the golem in a squad before beginning the transformation. I'll also let you know that, due to a modding limitation, golems can't leave burrows if your civs are restricted to them by an alert, which does reduce the military effectiveness somewhat if you use burrows to protect your civs when under threat.