It reads "use lore instead of fight in combat against the dark pharaoh". Can you use weapons, too? or purely your lore?

i have not fought the Dark Pharaoh (Surprisingly) but It is a Lore check and combat weapons only help combat checks.

I hope this didn't sound mean...

Tnx, I figured as much.

One more question: I just need to be sure- do you have to devote a hand for Bullwhip in order to use its exhaust to reroll ability?

Yes. you must devote one hand to the bullwhip to be able to use it.

Kroen,

With regard to combat checks against The Dark Pharoah, you use the skill Lore instead of Fight, but you may certainly use weapons. The entire enterprise has changed. You're still engaged in Combat, you're just utilizing a different skill.

As to the use of the Bullwhip's "Reroll" ability, you need not devote a hand.

The Professor

Some contradictions here, but I tend to go with The Proffesor, because this is how I played. No offense RabiTampa

Actually both of these questions have been answered in the Kevin Wilson FAQ:

Q2. Can weapons be used against the Dark Pharoah ("Use Lore in combat instead of Fight") monster token as normal? I see no clear rule why they couldn't be, but it feels a little silly to use Lore with a Tommy Gun.

A2. Yes, because you are still making a Combat check. You are merely using Lore to make it instead of Fight. Presumably you're coming up with clever ways to use the items.

I couldn't find the specific for the bullwhip but I found the one for the cross:

In order to benefit from the '+1 to Horror Checks' secondary ability of the cross I assume that a hand must be devoted to it for the entirety of the initial combat round. Am I right?

Nope, the Cross grants its horror bonus at all times, regardless of hand assignment. This is an official answer, BTW.
The hand assignment is strictly for combating undead monsters.

The Prof and Werepanda have it right. However, there is the issue of the Ritual Knife, but I believe it's the same: you get the +1 to spell checks regardless of if it's equipped (so you can use it for non-combat spells, for example).