I think it more has to do with engine limitations than "bugs", for example there's a lot of clipping when you build on angled terrain. Remember, this is a game engine, not a video game, limiting controls and freedom isn't a concern for editor. You can just lower/raise the terrain if there's issues appearing (Water only goes for like -24 to 24 height wise, so I don't think extreme use height was intended for the campaign and game, but felt the should leave the option for map editors). If you haven't noticed, all maps so far are completely flat and have no variation in high besides for cliffs, this may change in the campaign, but I also expect it will have no build zones in there's areas to prevent clipping.
The "professional" game art forums that I cruise tend to be pretty blunt and straight forward (professional in the terms that a lot of the members work for major studios (not professional in the terms of formal and mature conversation)), guess I've gotten in the habit of short harsh posts, sorry 'bout that.
I was mostly bothered by the use of the word majority. Limiting yourself to one way of doing/thinking about nothing is never a good idea. Looking at photos and real life reference = good idea. Always using photos for texture = bad idea. Abusing crazybump = bad idea. The face would have to be perfectly lit, and should really only be used when you're trying to model someone in particular.
$300 isn't enough, you'll need a decent video card, and processors speeds don't just multiply, a 3.2ghz x2 would out proform a 2.8ghz x4 most of the time. (most games aren't optimized for more than 2 cores).