For all bosses in other OSRS Gold, they were designed to be used without gravestones, with actual risk. A grave without bless lets you reclaim things from Bandos, KBD, Chaos Ele, Mole and apparently Zammy. DKs, Arma, and Sara are available in a grave with bless.
Graves also reduce the likelihood of RS in a significant way. We understand that people won't bless your grave to get their hands on your rage. Penis is not the word used to describe them. This is the way that the RS death penalty works, which has been distorted because of graves.
The blessing was not meant to replace friends picking up things and returning them, but a way for friends to help you out in the event of your death. The answer is easy, there are three choices. Limit your risk to what you can afford to lose, hopefully we'll see a reducation in the number of gear players who are maxed out at bosses due to the fact that there's a slim chance they could lose the gear.
Boss with friends - this is what people did before graves when they were looking to take less risk. You can continue to have fun with your friends like you're currently doing, but realize that if the bless goes you will only be responsible for yourself as I will be eating random strangers fat loot heaps. I hope this is completely clarified.
When the old wilderness was around (this was years ago I'm talking about), the PKing community in RuneScape was a decent group of people. We first asked "dm?" First, we asked "dm?" before we fought anyone. We wanted them to be ready and to be able to have a fun, fair, and uninvolved fight.
Also, people actually have dm'ed. It happens too often in RuneScape that I will ask someone "dm?" In order to receive an "sure" answer, or "yes" and always have them Buy Old School RuneScape Gold to the bank within a couple of minutes.