1) Take potions out of the loot chests, you already have a separate chest specifically for potions so they don't need to be included in the gear chests.
2) Change the loot tables to be dependent on the currently selected characters level. ( Not prestige or # of promotions ), then place that within the tier system. Characters level 1-8 receive gear levels 1 - 10, Character levels 9-16 receive gear levels 9-17, 16+ receive 16+ gear. The overlap is to account for transition and unlucky loot rolls (even within a smaller widow like this).
3) Salvaging gear gets you crafting materials based upon the tier of gear you salvaged. Tier 1 gear gets you Tier 1 materials and so on. Common gear gives a 1:1 gear to material ratio. Uncommon is 1:2 and Rares 1:3. All runes give only cloth with the same ratio spread based on quality of rune. Alternatively, expand the range of rune options beyond extra damage, breaking down runes gives the same mats as SP, essences, and let us learn schematics for adding different effects, immolate on hit, guard on hit, etc.
4) Rework the armor selection completely, com-plete-ly. Not that I don't enjoy some of the armor set graphics, but expand the wardrobe to allow us to customize it a little more. Give us helm slots, let us choose through the vast selection available in SP, all requiring crafting mats to make of course.
5) Allow the option to add an upgrade slot to a weapon that doesn't have one. I,e; The 2H dragon sword only has a rune slot available. For 50/50/50 you can add a pommel or grip slot to it, increase the requirement for an additional slot, providing that weapon class has available slots, no putting pommels on daggers for example.
6) Buying chests with platinum should carry a certainty of getting uncommon/rare gear, that would make spending actual cash worth more to us, the players, and more revenue for you, the developers.
These are just some of the ideas I've had while getting into MP (X360) the last couple of weeks.