I think this server you're planning to open can be huge given that you will make a good advertisement before opening it to gather players or to at least get their attention. But Playwith might probably stop you from doing that. So it is safe to say that this is not really the right time to open because of the RohanSEA hype.
My suggestion about the server is that, make it PVE/PVP. Have IM items, it is necessary for the survival of the server itself. Don't listen to those people who keeps on saying "Your server is pay to win" blah blah blah. Unless you have donate items. Also, if you are going to analyze, having IM as the source of income instead of donate items, IM is better for long term goal.
People who can't afford IM items must be able to farm in your server. They can sell items thru EM or via their own ways so they could get money to buy RPS. Remember that there are two types of players, farmers and no-time-to-farm-but-wants-to-get-strong players. If you observer in RohanSEA, both can survive the pay2win system by selling in game items and buying RPS etc etc. It benefits both the players and the server. I'm not saying that you must make a pay2win server but at least make it balance to attract both the farmers and cash players.
Balance the skills. Make them self buffs only. It is better as I can observe in RohanSEA. All classes can solo farm with the right build and right items. I think you can just copy the RohanSEA skills because they are quite balance, maybe needs just a little bit of modification.
If you are planning to make it a high exp rate server, remember that the drop rate must be also high. Gearing up and leveling must be proportional. Or at least don't make the leveling faster than gearing up.