So she moves double her speed and get free searches on search tokens passed.

Is is possible to increase the movement somehow? I guess you cant interupt it to do a move action and gain addiontal movement points (since it is not a movement action) but would it possible to for example spend fatigue during that action to move further and possibly get addiontal free searches?

What about other sources of free movement like treasure hunter trinket, the boots that provides 1 mp per tur etc?

Also, it doesnt say specificly say that she gets free search actions, just that she gets to search, would that stop the overlord from using cards that can only be used when a hero player uses a search action?

So she moves double her speed and get free searches on search tokens passed.

Is is possible to increase the movement somehow? I guess you cant interupt it to do a move action and gain addiontal movement points (since it is not a movement action) but would it possible to for example spend fatigue during that action to move further and possibly get addiontal free searches?

What about other sources of free movement like treasure hunter trinket, the boots that provides 1 mp per tur etc?

Also, it doesnt say specificly say that she gets free search actions, just that she gets to search, would that stop the overlord from using cards that can only be used when a hero player uses a search action?

The heroic feat is not a search action, so any card that triggers "when a hero performs a search action" wouldn't work. However, anything that triggers just off of "when a hero searches" would apply, I believe.

The heroic feat is also not a move action- by the way, this means it wouldn't be stopped by immobilize. I see no reason why fatigue couldn't be suffered before the heroic feat to give her a head start, but since she's "moving her speed" and not "spending movement points," I don't think it's acceptable to interrupt and spend fatigue for additional movement points- just like it's not acceptable to interrupt an attack action to fatigue move. However, if she had an item or class skill that increased her speed, that would apply.

She could suffer fatigue to gain movement points, but those movement points would have to be spend outside of this ability and she wouldn't be able to get the automatic searches from them.

So no, the movement from the heroic ability where she gets to search tokens on her way past them can not be increased beyond double her Speed. (Now, if her Speed was increased above its base amount, that's a different story.)

Cheers guys, thanks for clearing it up