ET3D: Which old school RPG's had ton of keyboard controls?
The Ultima, Wizardry and Bard's Tale series. The Wizard's Crown series, SSI Gold Box (Pools of Radiance, etc) and anything produced during the 1980's and most games of the 1990's.
ET3D: Normally most stuff could be done with the mouse, and keyboards were used for shortcuts, but it's possible to do without shortcuts. True that right mouse button use was common, but it shouldn't be too hard to simulate this.
The problem with touch-by-finger (as opposed to touch-by-stylus) is lack of precision (since you can't see that part of the screen covered by your finger). So buttons need to be bigger, than with mouse or stylus operation and pixel-precise pointer positioning is a no-go. Bigger buttons means fewer can fit on-screen, so either fewer commands or submenus galore.
Consider NWN2 with its Quick Spell selector (a grid of small icons laid out by level, which could reach 40-50 icons for high level spellcasters) or the inventory screens in NWN1/NWN2 - both these rely on precise pointer navigation to work and neither would be possible with touch-by-finger. So a commitment to touch-by-finger support (which is what phone/tablet support really comes to) means having to discard such options.
This is why certain game genres (like RTS' which rely on rapid and precise selection) tend to be far rarer on mobiles/tablets.