A 'poor persons' HDR can be done with ONE good photo. Load it into a decent photo editor, and adjust the exposure down two stops and save it, then repeat again but up 2 stops. Now with the 3 copies, run it through a HDR generator. Not as good as bracketing directly in the camera, but can yield acceptable results.
No. This will give the visual effect of HDR (which many think is something to be avoided - HDR should be a tool, not a style), but does not increase the actual dynamic range.
That only works if you're shooting RAW. And even then all you've accomplished was a convoluted process to achieve the exact same thing you'd get in Lightroom by adjusting the Blacks and Whites sliders, and dragging the ranges horizontally in the histogram.
Really, if you are going down that road I prefer manually blending the different exposures in Photoshop. 5 years ago, that is how I dealt with bracketed exposures as well. Back then HDR still had a very definite look which I really tried to avoid.
