1st off, if you're happy with "pul+", then stick to nightmare rushes. My last 2 nightmare forges yielded pul & um. Yes, you can get junk, but it's faster, less risky, less chance of people scamming, etc. If you're after the "mal+", then you do the hell rushes.
Public people scam ALL THE TIME. Once you've completed meph in a3, and are making you're way to the hellforge, they will leave. I know that is the typical way you "rush for forge" but it is very foolish. You CANNOT give them a1, a2, & a3 for free like that! They will simply make open public games called "help with diablo", followed by "help with ancients", and keep the forge for themselves.
Here's what I do: You demand collateral! You have to set up some exchange after each act boss. For example...
- after I kill Andy, you give me lum
- after I kill Dury, I trade the lum for your ko
- after I kill Meph, I trade the ko for your fal
- at the hellforge, I give back fal for whatever drops
You get the idea. Maybe those runes are too low for you... or too high for the person being rushed. Whatever, you make a compromise. Even if it's you holding one of his items, or whatever. The point being that if he suddenly leaves, you at least have SOMETHING!
A2 is the longest, and by far the most work. Maybe not the most dangerous, but clearly the most work. This is why you need to establish yourself holding something after Andy. If he leaves after Andy, no big deal. Teleporting thru the catacombs wasn't such a waste of your time. But if he leaves after Dury and you have nothing... you'll be pissed :-/ .