Hmmmm, not sure you have this one on the mark afpe as there appears to be a lot of speculation. [:-]
Probably worst is the thought that one's personal (or group) experiences somehow defines reality for everyone else so that if it is different elsewhere than it must be because "THEY" don't quite get it or have the skill/ability that "WE" do. [:-] For the record:
1. A number of the complaints have come from people that are well seasoned RC Flyer's who normally fly some pretty hot planes based upon information from their post(s). Yes, there have been a number of people who are new to RC Planes that have posted as well but roughly 40-50% have been people who are seasoned pilots that know what they are doing (based upon this and other boards). It is unclear what you mean by "young flyer's". If the indication is toward "green" or newbie pilots (as we called people in the Army) then yes there are those that have had problems, of course it would not make sense that you would be referring to "young" as in age since the indications based upon the overwhelming majority of posts would be that they are mature adults. [:@]
2. The instructions tell you not to fly in winds beyond 10 mph. I nor anyone else has made this figure up, this is what PZ has put in their manual on page 13, Success Tip #1 AND on page 7, Step #9 where they suggest 7mph or less. So you are insinuating that people should go beyond the boundaries prescribed by the manufacturer for their product and then question or chide them for potentially poor results simply because a group of other pilots can do so successfully.
This is not a fair basis for judging a pilots minimum flying credentials in application to the PZ P51. PZ does an admirable job of telling us what the minimum flying credentials should be for this plane and being able to fly in winds beyond 10 mph isn't one of them (although it of course does have some indication toward a pilots ability, I for one flew 4 successful flights doing loops and wing overs on "A" dual rate setting yesterday in 15+ mph winds (or 0deg angle on the ribbons, LOL!) but I still would not consider myself a good pilot. [:@]
3. The COG parameters were not included in the instructions so there was either an oversight by PZ and/or PZ did not think that it was needed since they designed the plane and obviously would have taken COG location into account. You can get the COG information on PZ's website and many pilots have checked or asked for this information just for do diligence anyway. [8D]
4. Many of the post that ask about the COG location indicate that they have had lack of control or erratic control responses and as such hypothesized that these control issues could be due to inaccurate COG location.
5. A high percentage of the post where trouble has been indicated have noted that they have endured inconsistent quality control issues. These have NOTHING to due with a pilots skill level but these are actual physical problems such as: Unglueing of aileron tubes, internal aileron cable corrosion, inconsistent down thrust/right thrust angles, electronics failure, battery hatches falling off in mid flight, sudden/unresolved range issue, charger malfunctions leading to melted batteries, a rash of broken props on good/flared landings, screws either too long or fitting receptacles too short so that the screws dig into the Rx and cause failures, pinions slipping off of their shafts, etc. These issues are physical and have nothing to do with pilot skill or experience (although some CAN be exasperated by too many very rough launches or landings, LOL!). [:@]
So while it is evident that a number of PZ P51 pilots are not experienced it is far to great of a jump to list "all usa flyers (mostly novices)" with the assumption that "we" just aren't as good as "you" guys across the pond or that "we" don't meet the prescribed minimum requirements as listed by PZ in order to fly this plane. [8D]