I RARELY was low on ammo, almost never was without when I really really needed it. I did not play on the most severe difficulty though.
As far as "make it like RE1,2,3", and keep in mind I never played them myself, but wasn't a HUGE part of the "horror" and tension a result of the fixed camera and horrid controls? I think if some parts (probably the Leon S. parts, from the looks of it thus far) slow it down a little, reduce the volume of enemies at a time and lower the available ammo count, it can bring a little more tension and fight or flight back to the game.
Also, I want to be able to move while I aim/shoot. At least as quickly as I could in Dead Space1/2.
ETA: As far as I'm concerned, they should lift the Dead Space experience and slap it into the RE world. Those games control beautifully, and (particularly with DS1) paced the enemy battles/ammo counts perfectly.