Nord Invasion about to fizzle out.

[Stillicho]

Big issues include the ease of the game and natural progression of time.

At this point, many veterans already have a T4 of every base class, or even multiple heroes of certain base classes, and interest in lower difficulties has dwindled. Without an infusion of new players, most are simply done with Normal.  The ripple effect is that availability of items from Normal drops, and the perception of its value increases leading to increased prices. And suggestions to implement new modes, maps, servers, or whatever for newer players won't exactly work. Players will just outgrow that mode as well, and the net result is you swap one headache for another. Look at any online game that has attempted to add a "new player zone:" as time progresses, those zones for low level players are completely desolate, and any new characters or players are usually friends of veterans that get power leveled anyway (this happens in NI too).

I think lowering the requirements of Hard mode to T3, and increasing the difficulty of Ragnarok would help. The mod would keep players engaged longer, allowing them to progress into Hard earlier, and keeping players interested in Ragnarok for longer.

This.

Any game over time progresses along with the ecomony or it crashes. Look at any mmo economy by comparison. Without something to stimulate a new player wealth and push them along into helping them get craftables at least instead of muddling along with no wealth at all until they lose interest in the game.

Right now there are either the super wealthy, who have gained there wealth due to a lottery-based system over time and the poor that grind. Those in between grind for a long time and have a lot of patience.

Boosting the economy of newer players would give them hope. You could do this through either increased xp gain in normal servers, which as it stands right now is a ridiculous grind for new character. As far as getting craftables, boosting HM drop rates would be a decent idea, just not enough to crash the economy as it stands now.