Not the OP, but since I worked with the FFL for 2 years, I'll answer your questions
In the past, it has been said that "The Legion is only as good as its worst German", reflecting on the large role that German members have played historically. Do you feel this still holds some truth?
Not at all. While right after WW2, many ex-german soldiers joined the Legion because they had no where to go, it's not the case today. So up to the early 60's , there were quie a few Germans. Today's Legion reflects globalization. You'll find Legionnaires from all corners on the world. If anything, you'll see quite a lot of guys from the former eastern block.
What are the current rules for Frenchman joining? Do they still need to assume a Francophone identity such as Belgian, or has that been relaxed? If the former, can they admit they are French later one once they normalize their identity?
Frenchmen can and do join as well. While this may have changed ( this was 20 years ago), you could remain a French citizen after you left or adopt a new nationality including Canadian.
How does the Legion currently treat the Algiers Coup as regards its institutional memory?
To some extent there is still some pride attached to it. especially if you talk to the older Paras/Legionnaires. . But otherwise, it's a non-issue
Historically, the Legion has been one of the few thoroughly professional units of the French military. With the French, as I understand, moving away from conscription and looking more towards a volunteer army however, how do you feel the Legion will fit into the military landscape of the future?
The French government has moved from conscription to an all volunteer professional army for at least a decade. The Legion works with all branches of the French Armed Forces. As a matter of fact, the FAR (Rapid Deployment Force) includes a Legion regiment.
Combined with being a professional corps, the foreignness of the Legion has also made it an attractive tool for French policy when needing to commit troops to possibly violent overseas regions. Is this something that Legionnairres are proud of - being the "go to guys" for danger assignments - or is there some level of resentment within the force that, taking into account of course you signed up for this, you nevertheless are being used for missions that they might not want to risk Frenchmen with?
That's another myth. The fact of the matter is that actions taken by the FFL are actions taken by France. The French gov't isn't sending legionnaires willy-nilly to do dirty work. Understand that even in the FFL, there are certain units that do very specific tasks. They have an equivalent in the French Armed Forces. So, many special operations includes other armed forces units. While the FFL is very effective at what it does, it's not necessarily to "go to" guys. It's like the Navy SEALS. While it's a top outfit, there are other specialty groups that are very effective (Rangers, Special Forces, Etc).
As far as being sent out because France doesn't want to use "Frenchmen", that's absurd. It's akin to saying the US Marines rather send blacks and Puerto Ricans to the front. For one, there are lots of French citizens in the FFL, second, as mentioned before, the FFL is French and acts on behalf of France. In the eyes of French society, there isn't a difference between a FFL soldier or a regular soldier.