Here are some ideas I had some time ago that I
think would help meshing RPG and roguelike:
1: An outdoors map rather than a dungeon (AFAIK FFHtR and GearHead do that)
1.1: You can still have dungeons scattered here and there (FFHtR does that too)
2: A sufficiently pool of "story relevant" places from which some are drawn to create a randomized plot (I don't think that a wholly randomized plot would work / I don't know how the fork you make that)
e.g.: Imagine such a pool consists of a
"natural" monster lair,
an advanced civilization's remains,
an ice palace, a lake and a town.
(no TvTropes trap for those two ; )The game could draw monster lair, advanced civilization's remains and ice palace. Then you'd have to go to the monster lair, clean it and grab a McGuffin that let's you access the advanced civilization's remains. And then there you'd get another McGuffin that lets you access the ice palace an beat the Big Bad in there.
For sidequests, there could be creatures (npc's) that are looking for whatever McGuffin / trying to accomplish whatever goal, for the most inane of reasons (as always, Inconsequentia is called like that for something) and you can help them out. Or not, and butcher them for the sweet, sweet XP and loot.
To beat some sense into such absurdity, places, creatures, items et cetera could have some "flavor" traits, e.g. firey, electricky, crafty, spooky, techy, whatever; and so a frosty magicky big bad would live in a frosty magicky castle, surrounded by frosty magicky countriside populated with frosty magicky underlings such as
evil penguins and snow golems (which might be friendly if you share such traits) ; and require a Firey Mighty or Firey Techy McGuffin/artifact to defeat. Such an item would be guarded by a
Threshold Guardian which need only share one of the artifact's flavor traits (firey, mighty or techy) thus giving room for variety.
Another interesting idea would be
generating the game environment AROUND the character: You could make a spooky, techy hero, and the game would generate holy and/or magicky bosses and plot-relevant places to defeat/overcome, and maybe place a spooky foresty monster den or a techy electricky ivory tower where you could equally rest and make friends or go rampaging around.
Basically, using elemental rock-paper-scissors with at least two sets of both conventional and unconventional "elements" (flavors/themes) as a way of giving some shape and sense to a randomized story.