It's an interesting question because it goes to assumptions behind turn based play. People make comparisons of roguelikes to chess and wax poetic about the time spent in suspense and consideration, but I don't think normal play really involves a lot of careful deliberation in combat -- the deliberation is in grand strategy about what equipment to use, how to act on information from mass reconnaissance spells, which dungeon branches you're going to visit in crawl, what your build is going to look like (stuff you think of outside of the game completely) etc. In other words, noncombat decisions where a reasonable game would apply no pressure to act quickly regardless of turn based or real time mechanics.
In other words, the amount of patience required to play at a high level is not that much on a turn to turn basis. Experience brings a different kind of patience: "You don't need to fight this guy now, if you fight him later, you're less likely to die," "You don't need that item so badly that you should risk dying for it," etc.
About your background on the question -- I think to really appreciate the genre, you should beat at least one major roguelike or major roguelike variant (use spoilers liberally, of course). The more interesting content tends to be packed in the late-mid and endgames and the design and balance issues come into focus best at the end (in my opinion).