As has shown my interest in my own grandfathers, you can trust the description of events, names and places but dates are often wrong.
Bordeaux was evacuated by the Germans in August 1944. Part of the garnison left for Germany across Central France and was partly captured here, while the rest reaches the new front established in Eastern France in fall 1944. The other part of the garnison remains in Bordeaux area but not in the city. It holds both sides of the Gironde river (so denying the access of Bordeaux port to Allied ships) until April 1945 when French took both German positions.
No unit in these Atlantic "Festung" was able to retreat accross France after they were surrounded. None ever try to be precise. So your father probably was part of the 1944 retreat.
You "late 1944" picture is obviously taken during the summer.
As for the other points of the story,
_ "But a commander futher north had not succeeded in destroying the bridge and americans where comming that way. Rumour said he was shot for the neglectance."
This probably refers to Remagen bridge, taken on March 7th by the US.
_ "During the retreat they moved forth and back on small roads and through forests in order not to be involved with the enemy. Though from the start of the Moselle upto Koblenz they had regular contact with the enemy."
Most units retreating from SW France in summer 1944 use small roads to hide from Allied planes, and not from Allied units that were not there. Taking such small raods increase the risk of guerilla ambushes, that were responsible for high losses and sometimes capture of entire units, but the air danger was worst. From Moselle to Koblenz, the unit should be reintegrated to the frontline and so have fought a slow fighting withdrawal.
_ "My father has bad memory on the exact dates. But he remember that he was at Koblenz on his birthday March 13. He thus got wounded on March 14 1945."
If he remembers his friend's name, you can check his death date (and place) at http://www.volksbund.de/graebersuche/content_suche.asp
_ "As for the Lancasters, I am told they had 16 rings on their gun, one for each confirmed hit. I will ask him again about the Goebbles episode."
It is perfectly possible that they were told that they shot down 16 bombers but the number is probably much lower. They were hundred of guns in Berlin area during 1943 and they shot down less than a hundred bombers. Most of the planes lost in the area were shot down by night fighters. And of course it was almost impossible to say who shots down who in the Berlin battles of late 1943.
As for the Goebbels visit, I will say that is classical propaganda show, as do all politicians and generals everywhere. "Well done chaps, continue like that, what would you like to have to do a better job ?" And the answer is forgotten by the big guy as soon as it has been said. The fact that they received a new gun is propably unrelated to the Goebbels visit, but rather to the fact that RAF raided many times Berlin in late 1943 and so defences were reinforced. The dancing girls are porbably the only part where Goebells (or rather his subordonates) have done something.
To end this long post, my best advice would be to post anotehr question about wich SS unit was in Koblenz area on or around 14 March 1945. The Flak unit of your father may have changed of name (becoming a PAK unit) or be included in a Kampfgruppe. So ask for any SS unit and for the commander's name. Names may remember somebody to your father. Once you have an unit, dig in the archives. And find more people and place names.
One of my grandfathers served in the French Army in 1940. His story was rather confuse but after a long time he said that soldiers from Madagascar were in his unit and that he trained in Perpignan, S France. By chance only one unit in France has soldiers from Madagascar and this unit trained in Perpignan. So I was able to find in the French archives the story of the unit and the name of my grandfather, who was a sergent and a squad leader. And I then provide him with a map of the area of the last battle of his unit. That brings far more memories of his past... and the final story was far more precise and bloody than the initial one.