First, let me tell you where I'm coming from. I got my instrument
rating and my CFII in an airplane equipped as you describe, and I
taught an instrument student from zero to the checkride in another such
airplane. Further, I know at least one other pilot who got an
instrument rating in an airplane equipped that way. So - the first
thing to know is that it is entirely doable.

Second, I think you're approaching the problem correctly. All your
ideas look good. Let me give you some other pointers.

When dealing with a cross-radial stepdown fix, try to give yourself as
much time as possible. A 172 with a notch of flaps flies just fine at
75 KIAS. That's a good speed to be flying when doing a full procedure
anyway - gives you time to think and maintain good SA. Anyplace where
you need to keep your speed up will have RADAR vectors to final. No
reason to go 1 minute outbound after crossing the IAF - you have 10
miles. Take 2-3 minutes before starting the procedure turn outbound.
It will give you a nice long final so you can nail the heading - and at
75 kts, you can't go far off course while you crosscheck. Of course
none of this works when you get into a faster airplane - but a faster
airplane will have better nav.

The VFR GPS makes flying IFR with such a setup practical - as long as
it works. That means you need to be sure your student knows how to use
it effectively, but also knows how to get by without it. For example,
most GPS units give a direct readout of track. That lets you know
right away that you've nailed your heading - or not. You can also set
it to that radial crossfix. Then, when you're 30 seconds from the fix,
hold your heading (and you can monitor the GPS to make sure you're
holding course and track as well) and take the crossfix. Amazing - you
checked at just the right time, and it is centered.

You will basically be training 3 approaches - VOR, LOC/LOC BC, and ILS.
You might find an SDF or LDA, but that's basically the same as a LOC
and everything I say about it will apply.

Remember that on the ILS, GS intercept at published altitude is the
FAF, nothing else. Don't wate time here flipping back and forth.

The only LOC you will be able to do is the kind that uses a
cross-radial for a FAF. Find one in your area, and practice flying it.
Doing this approach without GPS will be the biggest challenge your
student will face.

With a limited setup like this, good SA is worth its weight in gold.
At first the GPS will help, but wean your student off it quickly. He
should be able to point at the approach plate and tell you where he is
on it at any time - not at first, but before you're done with him.

A good ground briefing is worth its weight in gold here. Start out by
only doing one approach repeatedly, let the student know which exact
approach that will be, work with him to figure out exactly how it will
be flown and where the crosschecks (if any) will happen, and have HIM
brief YOU on the approach before you get in the plane. That will very
quickly develop good SA.

Find your examiner early. The PTS is very clear on this subject, but
some of them still insist that you need ADF, GPS, or DME. They are
wrong, but it's a lot easier to find a different DE than fight it out.

Remember, both GPS failure AND vacuum failure together is a very rare
event. Do teach your student to do a VOR and ILS approach partial
panel and without GPS. Don't waste your time teaching him how to do a
LOC or VOR with FAF defined by cross-radial that way - it's just not
worth it, unless the student is doing really well and you have the time
to do it. It's a great proficiency exercise, and will make a great
exercise for recurrent training, but the likelihood of needing to do it
is just about nil.

Michael