you are right it can increase your charges against you and it doesnt even have to be an illegal drug in alot of states being intoxicated and in the possesion of a hand gun can increase the charges also, that doesnt stop alot of people from doing it anyway, so its probably not a good idea to carry a gun on you anytime you may have drugs in your possesion.
as per owning guns at your house dont really see that its that big of a deal have known atleast a couple of people who have got charged with cultivation and possesion and did not get into any more trouble for having guns in their house but im sure it can vary from one location to the next.