I assume that the fourth suggestion is to update to Renewal/current RO updated status. If that is the case, then both the first and the fourth suggestion are renewal related. I'll try to elaborate why this isn't easy to do or even an option that has been considered but not carried out yet.
For the first suggestion, a new client would have to be created. Sadly the way we use the client and the files that come with the client are uniquely coded. This way of coding isn't available anymore for the renewal clients. What does this mean? All customs (mobs and items) which were indirectly linked to the client aren't linked anymore. A whole new system of adding the customs would have to be created, setup and converted from our current database. Because such a tool doesn't exist, all the customs would have to manually be converted. This isn't worth the gain. In the past (about... 2? years ago) I have successfully created a renewal client and logged in to the game, but it ended there. Nothing was usable, the way maps were displayed were off. Skills weren't recognized and nothing worked the way it should have been.
Having looked at the current progress, not much has changed and actually most of the development on those kind of game clients is dead on eAthena. I think jAthena was making small steps forward though..
Might all sound a litlle... yea not completely structured, but I hope I got the message across. So because of this, upgrading the client isn't an option (at the moment!)
For the server upgrade, some of the explanation above applies here as well. Because the improvements and mechanics and all that comes with the gameplay of the classes, skills, usage of items and all that aren't completely working yet, it isn't favorable to migrate to a renewal system model yet. It already is very generous of Genesis and the other staff members to provide the community as much of renewal as possible by customizing the content and implementing this. But because a class balance has yet to be obtained in Renewal (without high stats), it would naturally snowball even harder on a server with high rates and stats. Due to the attempt to preserve the balance in this server, the migration to renewal isn't an option either. At least, not now or the few months coming, but will be in the future for sure. Knowing how things go, everything will be done to make it possible, so don't worry about that!
The other suggestions have been enlighted fairly by Bishop.