Yes, the danger in lithium batteries is not with lithium primary (non-rechargeable) batteries; it's with lithium-ion and/or lithium-polymer rechargeable batteries, and even then, the risk is highly overrated (most instances of Li batteries exploding during charge is due to damaged batteries, such as a battery pack re-used in R/C planes after a crash, or when recharged as a pair when one is defective/mis-matched...always recharge Li batteries as a marked set, and occasionally test them).
On to the question of voltage vs current; the
internal resistance of a battery also plays into this. NiMH batteries have all but taken over the spot held by NiCads, except in some high-current-demand situations. The internal resistance of NiCads is lower than that of any of the batteries discussed so far, and so they are able to supply a high current without dropping their voltage as much (Ohm's Law...V=IR). As such, they are still king in certain high-current applications, such as powering servos in robotics. But they weigh a lot more, and they have the infamous "memory effect."
All of this is a balancing act; you can have long life, high current, or constant output...pick any two.
But all the available current in the world is useless if the potential (voltage) drops too low for the electronic components to use. Gotta have both.
BTW, this is yet another advantage cameras with the "evil proprietary" batteries have over cameras using AA's...the proprietary batteries are matched to the load and demand. There's no worry about what consumers might substitute, and the device was designed knowing exactly what the power supply's capabilities are.