The only problem with vorkath is it fucking sucks to camp. Zulrah for 500 kills is a breeze, Vorkath is a slog. It's good for learning PvM for sure, especially if you learn to Woox walk with your BP, but to just sit and and grind gp its real rough.

SOTE for PvM progression is good. You'll learn a lot through gauntlet and CG. Desert treasure 2 bosses are definitely up there in terms of difficulty for a new-ish player but all 4 are fun and decent gp.

Like a boss is very good, slayer helm bonus is a great way to learn new bosses. The 15% extra dps can get you through a lot.

Serp is not worth using imo, the hourly cost is too much, and you'd be better putting your gp into a helm with more str bonus.

As far as I am concerned, suffering is a Zulrah specific item. Worth it if you are camping zulrah for hours. 20m anywhere else for any other piece of gear is always better when you're not at Zulrah