Heh, Im enjoying your questions, its either, everyone knows what I know, or noone cares what I know about this.
The 'newtype ace' I suspect, is Amuro they are talking about, in 08th. Him, and you could say the entire crew of the white base, were the only new types the federation had during the one year war. The newtypes were aces because they could sense what the enemy was going to do before hand. At the end of the one year war Zeon started producing mobile armors and mobile suits that had weapons designed to be controlled by new types, beam weapons attached to cables. The Elmeth, piloted by Lalah Sune, was the first mobile armor to use a 'bit' which is a small laser cannon with no attachment to the mobile armor that the new type controlls with their mind. By 0087 (zeta gundam) they were started to be used again, with Haman Karn and her Qubeley, by ZZ gundam, the majority of Axis Zeon mechs used this technology. Its this technology that destroyed the Red Comet's (Char Aznable) mech in Zeta gundam, the Hyaku Shiki (100 years, for those that dont speak Japanese)
It does seem more believable, to see them on the ground, but you need to realise the ones for space, were build for space, and the pilots trained for space combat. Go look at MS Igloo, the hidden one year war, the 3rd episode "Dance of the Orbital Ghosts" or "The Rapid Illusion above the Orbit" depending on what translation. Shows the zeon forces trying to retreat from the earth, and the federation, using balls and a few GMs, catching the ground type zakus in their escape pods and tearing them up because those zakus wernt built for space combat.
Even the gundams needed to be refitted for space (rx-79 and GP01 specificly)
As far as damage, the Zeon suits were almost universally made from Super-hard steel alloy which wouldnt take much damage from small arms fire, but tank shells, anti mobile suit hand held ordinance (See the one pic from above of the infantry), or suit weapons would all damage it. They most definatly took scraps and dings, armor is always armor, and paint is always paint, if ya get my drift, if you drop a kit and the paint chips, the mech's armor will chip as well.
The federation armor was almost universally Lunar Titanium alloy (to be renamed gundanium in homage to the origional gundam (an exception would be the CLASSIC GM another would be the BALL They were made out of plain old Titanium). The lunar titanium did protect the gundam from more, but not ALOT more, they still took damage from most weapons (as seen in 08th). The one you put up in the shot, the EZ-8 if you remember, is actuially a hodge podge of a few different mech's parts because there were no spares, the Rx-79{G} was a prototype with no replacement parts laying around.
As far as the animation, when your doing a large series like that, itd take to much for them to weather the mechs in every shot. Here are a few examples of modeler's interpretations of damage to a mech.
Paint chipping would be very common, so would dents and dings. Make sure you remember your scale for doing damage and weathering. Always keep teh 1/100 scale figure handy to give you perspective.
Also, modding mechs is a big +. There are so many variations out there, its encouraged to put your own spin a bit.
Check this site http://www.bakuc.com/ for inspiration. Search the gallery for Expert and Advanced, there is alot of junk around if you dont (including mine)