Just beat the Ruin Sentinels, once again wearing no armor so I could dance around them like ninjas ("Dude, that's Bloodborne as @#$%!"), although I did carry a shield this time I'm not sure you can dodge the 180* attack the sentinel does when it jumps back onto ledge, so I needed the shield to block it. I used an upgraded club to quickly defeat the first sentinel on the ledge, then did about half damage to the second sentinel, before the third joined the ledge and I left the party, rolling down below. It took a number of tries to learn all their moves, but in the end I exploited the long cooldown when they both did a move. This "naked club" build works well against the bosses so far, although I quickly put on all my armor as soon as it's back to regular enemies!
Oh, and regarding the mob in the tower leading to them I just ran past them all, which is easy to do when you're not wearing pants!
Man, it's satisfying to spend nearly 40,000 souls leveling up. I spent some on lifegems, but I raised myself at least six levels: two in Adaptability, one in Vitality, one in Endurance, one in Vigor, and one in Strength. Feeling good!