In an open world all our computers will crash, I had issues for a long time just loading eltibule map.

To be totally honest you lost me at "Like in UO". Those suggestions involve a complete overhaul of the game and the truth is most of us like it without the addition of open world PvP or losing items upon death (as someone mentioned already there is a hardcore system if you like the HC effects).
This is the first purely PvE game I've ever played and I would like if it had a siege system or anything involving mass PvP like in other games i previously played. But that simply does not fit P:G, there are too many limitations and the first big limitation is the developer's time and how he wants this game to look. I might want mass PvP (well GvG technically) but if I'd have it I wouldn't be able to move my char since 20 other chars using spells around me would drop my fps to 3. These are only 2 limitations and I won't get into more details about griefing etc. It's just not a feasible option for this game to be PvP centric, it's designed for PvE and changing that would involve a complete overhaul as I mentioned already.