So in using latex paint as opposed to oil based paint, what's ok if not just as good or better to clean the brush - only water and soap plus a wire brush or paint thinner also works just as well?
In thinning it out for use as if a stain, water or also denatured alcohol?
Well, I know that when I've cleaned up paint spills with thinner, it works pretty well, but it causes the paint to curdle. So, I would say that it's fine to use to clean brushes but not to thin latex paint with.
I would be careful of putting thinner on any brush that you plan on using for latex. It will curdle the paint and ruin the brush. You should always have seperate brushes for oil and water based paints.
On the subject of cleaning, soap and water and a brush comb, or brass bristle brush. Ivory laundry soap and Dawn dish soap do well, but Murphy's Oil Soap rules. I know it kind of goes against the oil vs. water thing, but it works really well and will eventually help keep the brushes cleaner.
I'll go with what has been mentioned already, there is no substitute for soap, Cold water, and elbow grease. The only thing used to thin Latex paint should be Water, or clear latex such as Roscos "Glazes" or Miller paints Acry-clear.
BTW alway use cold water when cleaning brushes, it might hurt your hands a little more, but cold water keeps the latex from setting up. Hot water speeds the curing process, and use of it, usally results in the congealing of paint around the base of the bristles and under the ferrule.