First off: Yes, you can be level 4 by the time you are in the goblin camp. You can also finish the entire Early Access at level 4. A Lot of the xp is in killing things though, Especially all the smaller encounters in the abandoned little town you go through.
For that fight specifically, remember that you can push people too, and you never HAVE to be near the spider pit if you don't want to
The spiders will enjoy any which meal they can get.
As for the game being too hard. I could imagine it being too hard for people, especially people that haven't played a whole lot of cRPG's in the past. I think most of what's causing the current difficulty is that DnD's armor system (AC ratings) doesn't really gel well with Larians unavoidable ground-effects. Low level dnd characters survive by virtue of not getting hit a lot. For fighters this means wearing a lot of armor and putting points in constitution, for mages it means staying out of harms way, and blasting away anything that comes close. Unavoidable damage that ignores AC ratings is therefor a bit painful.
My advice is to pay a little more attention to line of sight, if you're struggling with archers, it might be a good idea to pop a smoke-cloud of some sort over your party, and have your ranged characters pop in and out of it's cover. Have your melee characters ready to intercept and push away any annoying enemy frontliners. As always, kill the 'problems' to your tactics first.
Hope that helps!
