I know 10hp characters can do Shilo Village with provided recoils and such. However, I heard a rumor that it is best to have 'help' there, especially players to cast Vengeance. Is this really necessary or is it quite possible to do it yourself?

I did that quest too, but I don't have 10 hitpoints, but I do have 1 defence, and 11 prayer. Back then I had like 85 ranged and I had some trouble killing the boss monster when it was close. But somehow I got her stuck and ranged it till it died. Anyway what I'm trying to say is that friends might be needed to make it through, else it probably would be pretty hard. Note that you don't have to listen to this advice since I'm not a skiller, and maybe I'm bad with quests and stuff.

i think the higher lvl breaks kills most of the hp and you come on with sara brewed up with recoils and veng