Righto I'm a bit of a WW2 fanatic but unfortunately i tend to follow my nation and when i can get hold of other exploits they tend to be in Europe but my beliefs are that no the Germans could not hold the the Italian peninsula due to the fact that they were crumbling scarping the bottom of the barrel I mean they had 12 year olds fighting fer god's sake
You try to paint a picture with too large a brush. In Italy were located very powerful divisions concentrated in such a small area. Crack parachute divisions, a number of Panzer-Grenadier Divisions, the HG Panzer-Division and more, all under the leadership of Kesselring who would continue to prove himself throughout the campaign, being along with Walter Model to be considered perhaps Hitler's "Fireman", saving them in the toughest of situations. Although Germany did have manpower issues, I only truly feel that it was by June 1944 that it had become an insurmountable problem, more so once the Volkssturm had been formed.

that and they were running low on supplies Germany requires a lot of their supplies to be imported into their country and they couldn't do that as bascially the entire world was against then and they were surrounded is was unwinnable
It depended where you were really. In Southern and Western Europe, the troops were less hard pressed because it wasn't such a logistical nightmare to transport supplies through France or Austria in to Italy whereas sending them across the partisan infested Russia was hell. This wasn't helped by the fact that the railway gauge in Eastern Europe was different to that used by the Germans which required new rails to be laid entirely.

and no the British were not scraping the barrel n terms on men but the money the coffers were empty they couldn't afford it!
Yes they were in a money crisis, but they were short on men too. There's a reason that Montgomery was cautious in his planning, and that was to preserve as many lives as possible for the simple reason that by 1944 the British had practically exhausted their manpower.

literally and yes the yanks had what seemed an endless supply of troops and supplies but I believe that is due to their tendency to come in half way through because if you look at it Hitler had been turned in Europe Musso in Africa and the Japs in New Guinea (by the Aussies!) and coming in half way allowed then to have more men due to less killed in previous conflicts and therefore they were able to have more kids which could increase the population more and more and that population could fight more and produce more material.
The problem with the American replacement system however, was that rather than mixing in new recruits with the more seasoned troops, they simply sent in levies with levies. This resulted in morale issues, and less combat efficiency than what say, Germany would have had. Nonetheless, what you say does make sense since the US had simply an advantage in population and with the power of mass production could churn out endless quantities of material whereas say, the Germans with their more clunky designs had a much slower production rate. If I recall correctly, Tiger Tanks had over 10,000 separate parts, so scavenging off other vehicles mid-battle was impossible, whereas the Russians with their T-34s could simply find burnt out tanks and salvage equipment from them for the T-34s that had issues that needed fixing (but didn't remove them as a presence on the field, which would have required repair in a field workshop back in friendly lines).

and I know this is soon but it's a preemptive strike In both world wars the Aussies had the highest casualty rate took the most ground and inflicted the most damage on the enemy (men and material killed or taken prisoner/destroyed if you discount the atomic bombs) and did more.
Are you sure you're not on about the Russians?