First, a faction has to be eligible in order to play a Brilliant Stroke card. Does a faction with a the ability to trump that card also have to be eligible in order to do so? If the Patriots play a Brilliant Stroke and the Indians want to trump it but aren't eligible, can they still do so? My reading of the rules is that they can, but I'm not sure.
Trumping a Brilliant Stroke card is still the act of "playing" a Brilliant Stroke card.
Rule 2.3.8 wrote:
Trumping is the act of playing a Faction’s Brilliant Stroke card to cancel a just-played Brilliant Stroke card.
Thus, in order to play a Brilliant Stroke card, the faction has to be eligible.
Second, and this is possibly a stupid question, but if an event gives you the ability to free march forces to a specific region, do those forces have to already be within the range of a normal march (i.e. patriot or indian forces would already have to be in adjacent spaces like they would for a normal march command)or does the event give them the license to go to that space from farther away? For instance card #21 allows Patriots to free march and free battle in South Carolina and Georgia. Do there have to be Patriots already occupying adjacent spaces in order to use that event? My interpretation when playing it out has been that they do.
Unless the Event specifies otherwise (I don't think this is ever the case), you will still need to obey the rules. So if Patriots get free March, the units and territories you choose will still need to be valid as per the regular rules of March.