Yeah the Longsword is in a tunnel to your left once your drop down from the second bonfire in the Forest (Where the merchant with the blacksmith key was originally) - first tunnel had one of those turtle knights standing backwards. You have to time yourself to avoid the fireballs that the monster is shooting and enter a door to get to chest. As for the fire pit with the lizards - I didn't go there but I'm pretty sure you can get there by continuing forward in that pit area outside where you get the Fire Longsword.You're still in the readjustment phase. I'm finding the mobs more manageable now, in part because of increased stamina and agility, but also in part from a better sense of how they work.
I don't think I found the Fire Longsword. There was a tunnel with a fire-breathing creature at the end of it I should go back and check that out. And I don't think I went down to the pit with the fire-breathing lizards, the one near the bonfire. I'm not even sure -how- to get down there.
The first boss, Last Giant, is simpler when you realize you're supposed to target his feet. You can even cycle through different lock-on points. When he raises his foot to stomp, simply backing away will cause it to miss. Heck, you can even switch targets to his other foot and the one stomping won't hit you.
Is it good to have some ranged magic as well? Seems like it would be useful to pick off archers with. I'm just not sure if it's worth the investment in stats and whether it'll take away from my melee damage too much.