Lots of people try to push newer divers away from currents, but I don't see a problem for me. I've only done 1 dive with substantial current (Washing Machine in the Bahamas) but it was one of my favorites. We covered so much more ground and got to see so much more than other dives. I do see how it could be problematic, and wouldn't recommend it as a very first dive, but I didn't find it particularly challenging, intimidating or dangerous - just a little more important to listen and follow directions. Of course, bigger currents could be bigger problems.
I am a 200 lbs male, and while my air consumption improved over the 30 dives on my trip, it isn't great compared to 120lbs females. I had one as a dive partner that surfaced with around 1600 psi after a full hour, I was still over 800, and only went up because the other divers went sooner, and I bet many went below the 500psi we were asked to return with.
I have a much harder time NOT moving. My air consumption compared to others is a lot better the more active we are. I am in great cardiovascular shape even if I am less experienced, which pays off more the more everyone exerts themselves. But our dive master could hold perfectly still horizontally 6 inches from an interesting animal, while I tend to start flapping my arms like a bird unless I have some momentum.