6) Do away with inventory management altogether, or at least inventory space constraints. Also no crafting please. The worst feature in Din's was the amount of time you had to spend shifting stuff around in different bags, an issue still not completely fixed in Zomb. I don't know who originally came up with the idea that limited bag space is a fun thing in an RPG, but they have a lot to answer for! Diablo 3 sorta fixes this by giving you extremely generous inventory space. Getting rid of crap items (ie, not having crap drop in the first place) helps as well.
7) Related to point 6 - getting rid of crap RNG items. Fewer but better items is almost always good in an RPG. Work on the item generation algorithms a bit - rather than an item having a totally random (and therefore mostly useless) set of traits, how about having Trait A be totally random, but then Traits B and C and D are influenced by what Trait A is, so that the item has a definite theme or direction. For instance, is the first trait on Shield A a bonus to skeleton summoning? Figure out which characters actually can use skeleton summoning, and figure out what kinds of other traits those characters might want. The random selection of Trait B is then guided by that - it might be an increase in darkness, a straight bonus to defence, a buff to skeleton mages, or a synergistic bonus with other necro-leaning items... but it won't be things that skeleton summoners can't use or don't really want, like a bonus to strength or light intensity. In this way items can still be random generated, but they are more likely to be interesting and themed.
8) Shake up the stats a bit. RPGs are getting a bit tired with the usual strength/intelligence/dexterity (or whatever they are called) way of describing characters. And usually a character just maxes their main stat, with enough into dex and con to keep them hitting and alive, or whatever. Levelling up is often formulaic: 3 points into main stat, one into dex, one into con or whatever. Either just scrap all this and automate it (because the player isn't making meaningful choices), or rethink it radically and make the choices interesting and result in viable different builds. Imagine an RPG where the character traits were Ambition / Courage / Pain Threshold / Empathy / Balance etc., maybe 20 or 30 of them, and each one related to different skills in strange and interesting ways, and improving them was to some degree path-dependent or synergistic. Eg, improving "pattern recognition" gives bonuses to skills x, y and z, but decreases skills a and b, and your rating is capped as twice your "raw intellect", which can itself be increased... etc