You know, it really depends on what you are modeling. I'm a former tank commander, and think the "texturing" you speak of to be a little unrealistic in 1/35 scale. On some vehicles, there is definitely a "cast" or "textured" surface that appears when the steel is sand cast, but in 1/35 scale, it may or may not be apparent. Your best bet is to look at the real thing, either in a museum or in photos. In aluminum vehicles like the M113 or M551, there's almost no discernible "texturing" apparent on the real thing, so you wouldn't see it in 1/35 scale. Same goes for many other modern AFVs. In the case of rolled or pressed steel armored plate, like that found in armored cars, there won't be much texture either at 1/35 scale. So take a look at the subject to determine what might appear in scale proportions.
You said it Russ. But If we built things truly to scale the models would be uninteresting so some "exaggeration" is needed to bring life to the models otherwise they would just be lumps of plastic but people do take it to extremes.
How do you feel about scale anti-slip coatings? I think the roughest texture I've seen is on IDF vehicles, US vehicles look like heavy grip tape. But some products, if you scale it to 1/1 would have grit the size of the first joint of your thumb. On most 1/35 vehicles it would probably look like just a raised pattern in the paint but again to bring interest and life to a tank you would need to, and I hate to say exaggerate, but that is what you have to do.
I think a true "scale" representation of anti-slip coatings depends a lot on the scale. A few years ago I did a commission build of Revell's 1/144 Fletcher class destroyer, which has prominent anti-slip coatings on the deck. I represented these by a heavy dull-coating over decal paper that had also been painted in a "tire black" color. That was sufficient in 1/144 scale, but was probably a little exaggerated, and would be suitable in 1/35 scale in some instances. One technique I use for anti-slip coatings in larger scales is to sprinkle "Rotten Stone" powder over a wet clearcoat that's been masked off, then overpainting it. "Rotten Stone" is exactly what it's title implies-- it's a finely ground stone powder, about the consistency of powdered sugar. It can be purchased in any good hardware store (I get mine at Ace, but I've seen it locally at Mclendon's, I'm sure it's available at True Value, but I'm not sure about the big box stores). It's generally used for polishing. In 1/35 scale, it makes a pretty convincing anti-skid surface. It comes in a gray color, and after application I give it an overcoat of whatever color is needed. I especially like to use it for simulating concrete airfield surfaces in 1/72 and 1/48 scale (for dioramas), but it also works for 1/24, 1/32 and 1/35 anti-skid surfaces very well. I've seen folks use flour, but I'd be concerned about deterioration over time (or critter infestations-- I don't like to use foodstuffs for modeling purposes much-- don't ask why, but it involves some ground cover and some weevils). But again, to sum up, I think the best bet is to look at the real thing to determine the extent of texture visible-- sometimes all you need is a slight variation in paint to simulate texture.