I understand that the EIR pilot can desend to 1000ft above the highest obstacle within 5nm. Presumably this will always be lower than the minimum altitude for radar vectoring.
Where terrain clearance is limiting, MVA will usually coincide with 1000 ft above the highest obstacle within that sector of the airspace. While it may, in principle, be possible to get lower and still remain 1000 ft above the highest thing within 5 miles, it's not really something that the pilot should be expected to be able to do. Thus in assessing the conditions required, I'd treat the MVA as the level by which the aircraft must be visual. In transitioning from IFR to an arrival at an airfield without IAPs, that's essentially what one relies on.
As I've mentioned elsewhere, I think the mechanics (as you put it) of arrivals, and of departures for that matter, needs careful attention, including the detail of what goes into the implementing rule, the AMC and the GM. But I'm reasonably confident that a sensible solution can be found, even if it's not exactly what is in the current NPA. Let's just review what it says:
FCL.825(a)(2)
"The holder of the EIR shall only initiate or continue a flight on which he/she intends
to exercise the privileges of his/her rating if the latest available meteorological
information indicates that at the estimated time of arrival at the planned destination
aerodrome the weather conditions will be such as to allow compliance with VFR on
the approach and landing phase of the flight. On departure the holder of this rating
shall not enter IMC below 1000 feet above the highest object within 5 NM."
AMC1 FCL.825
"1. In order to comply with FCL.825 (a)(2), the holder of an EIR should not commence or continue a flight during which it is intended to exercise the privileges of the rating unless the forecast for the destination or alternate aerodrome one hour before and one hour after the planned time of arrival indicates VMC. If the required meteorological data are not available for the destination aerodrome, the flight should be planned to a nearby
aerodrome for which such meteorological information is available.
A VFR transition point
should be used in order to enable the pilot to conclude the flight under VFR to the
intended destination. For this purpose, when filing a flight plan in accordance with
operational rules, the holder of an EIR should include IFR/VFR transition points. If an IFR
approach procedure is established at the destination airfield, this IFR/VFR transition point
should be passed before reaching the Initial Approach Fix (IAF)."
GM1 FCL.825 En-Route Instrument Rating
"Since the privileges of the EIR are only to be exercised in the en-route phase of flight, the
holder of an EIR should:
1. at no time accept an IFR clearance to fly a departure, arrival or approach procedure;"
* The prohibition on "arrivals" is unhelpful. Arrivals are effectively an extension of enroute. Some "arrivals" start 100 miles away from destination.
* Visual approaches (under IFR) need consideration
* Departures (under IFR, with the first 1000 ft flown visually) need consideration
In an environment where radar vectoring is the norm, it seems reasonable to allow radar vectoring for a visual approach -- many if not most operational IFR flights are conducted in that way.
For a procedural environment, you probably do need to be visual by the IAF, otherwise you'll end up flying some of the procedure without radar guidance. If we're going to match privileges with training/testing, and the training/testing does not include approaches, it doesn't seem sensible to allow even the initial approach to be flown in cloud. Is it reasonable to allow it to be flown visually? Maybe, though it could still lead to errors and confusion.
I think the underlying principle should be that the EIR holder is trained to fly a heading to reasonable precision, to fly a level where there's 1000 ft margin or separation, and to do a reasonable job of tracking a navaid or to a waypoint. If their life depends on doing something more precisely than that, they probably shouldn't be doing it.
I'm not sure about departures. They're not fundamentally difficult to follow, but it is a high workload time of flight. I don't think it's unreasonable for an EIR holder to follow a SID, as long as it's done visually for the first 1000 ft or so. The idea of departing VFR and getting a joining clearance sounds overly complicated. I hate doing that, particularly in marginal conditions, and I wouldn't wish it on an inexperienced pilot.