From what I can see, this should work. There is no cross-checking, is there? The only people who might notice are the airports directly addressed.
A bizzare mental exercise but it shows how broken the system is!
Yes, no, yes, in this order. And nobody will care, VFR flightplans are mostly useless, anyway, apart from SAR, maybe.
Outside europe I bet you can even file concurrent IFR flightplans. After all, it’s just a strangely formatted email message on a prehistoric email system called AFTN.
What would be the goal of such an exercise? Or are you just discussing the system capabilities / lack of checks?
The latter
I see. That could become a long topic
Well, I can see a scenario where you may want to do it:
You are flying A to B, uncertain wx, and if the wx is OK or if you get some mad Eurocontrol slot you may want to go VFR.
So if you filed both…?
Normally, one would cancel the IFR flight plan and file a VFR one (if one is actually needed) but let’s say your internet connectivity is poor (often the case in the countryside) and the airport of departure is unmanned / unhelpful / unwilling to assist with cancelling a flight plan or filing a new flight plan (true for LFAT for example).
It is IMHO irresponsible to do such a trick but there may be a scenario where you may have to do so, when you have the opportunity to do it (say back at the hotel).
A flight plan that is not opened is a plan that does not exist from an operational point of view.
No issue really.
In Peter’s scenario (uncertain weather) could you not just file a Z plan and then not bother with the IFR pickup if you decide you want to continue VFR the whole way?
I guess this wouldn’t help you with a Eurocontrol issue though, eg if stuck on the ground waiting for a delayed clearance.
In the scenario described by Peter (uncertainty about WX) I would file IFR and just cancel if the conditions would would be VFR.
You can cancel at any moment.
I have this situation sometimes when flying with a VFR-only pilot. They usually suggest to depart VFR and switch to IFR if necessary.
But I prefer to do it the other way around because a popup IFR clearance is not always trivial.