I think the adjustability of a car can actually be daunting for the newbie. Entry level cars mean not only low prices but also relatively straightforward setup options so the newcomer is eased into on road car tuning as they learn driving. On road TC is probably the most difficult class in terms of tuning the car, so it can be very off putting for the newcomer when they take their brand new car to the track only to find it doesn't do anything right. Even basic cars like the TT01 can be a pain to properly setup with no knowledge of tuning when you're racing on low traction surfaces.

About strength, I would think that carbon fibre/glassfibre is more resilient than fibre reinforced plastic due to it's inner structure where the fibre cloth is continuous in two directions as opposed to graphite/fibre reinforced plastics where the fibre structure is discountinuous (or continuous in only one direction at best). There is also a bit of flex in carbon/glass fibre plate which doesn't exist in reinforced plastic parts.

As for the aspect, oh well, just whack a body on top of it! Or paint it black.
I see an advantage in parts being other colour than black. Any cracks will be instantly visible which is an advantage for me because I race in a club under fluoro lights and with a high ceiling you need to bring your headlamp to see little black things in other little black things. Just last week I have missed the cracks in both my front arms because of the poor light we have at the track. The car still went well enough that I won both finals, but at home there was a big surprise.