For me, it was about a 7 or 8 the first time I played it.
Generally speaking, Ravenholm isn't scary due to its lethal enemies, it's scary due to the atmosphere, dark visuals, and spooky sound effects. It's also unnerving to see the devastating effects of the Combine's headcrab shelling. However, Ravenholm probably won't be the section of the game where you die the most. (That dubious honor would probably go to Nova Prospekt) Most of the enemies you face are slow headcrab zombies, and there are plenty of physics objects to hurl at them. Fast zombies and poison zombies can cause problems, but they're still manageable.
Ah, thanks guys. I made it through a while ago, and died quite a lot less than I thought I would! I agree that it was the atmosphere that was terrifying, not any of the enemies. But the poison headcrab- throwing zombie in the corner of that town-squareish type place got me a few times.
I haven't played in a few days because I don't have access to my bro's computer, but where I left off I was just getting out of Ravenholm, and I have to jump down a mine-shaft looking thing where there are tons of poison headcrabs scuttling around. I get that I should kill them by shooting the flammable barrels, but I have literally no ammo. I tried jumping down via the rafters along the walls, but even jumping from as low as I could get, I still die on impact.
I greatly dislike using walkthroughs, and I haven't yet, but this part is really throwing me though a loop. *sigh*
La mia bambina cara, perche non passi lontana? Si, lontana da Scienza, cara, cara mia bambina?