Artiphon

The questions in the title is this a suitable instrument for learning to play music ?

I have found it difficult to play the guitar , the main barrier is the strength required in the fingers to correctly hold down a string , this would seem great way to alleviate this problem

Personal story: I got an I1, found it rather difficult, and proceeded to learn playing guitar instead. 

Particularly an electric is definitely a lot lighter.

Still: any fretted instrument needs a bit of commitment; The first few weeks (at least) it will not play the way you want, and barres take months. 

On the other hand, you can play the I1 laying flat on a surface in tapped mode, this way it's a lot easier (lighter) than guitar; but then you won't be able to directly apply a lot of the training material available for guitar (particularly: open chords won't work!).

So, personally I would answer "not much, better get an electric guitar to learn"

There were certainly people on the old forum who found the I1 much easier than a physical guitar for precisely this reason, that the touch required was so much lighter. I certainly find a single note on the I1 works with a much lighter touch than on even light gauge electric strings, and is also much more comfortable because the string doesn't gouge into your uncalloused fingers. But barre chords are close to impossible, and the bridge triggers are much less responsive than real strings, so it's mainly useful for learning the fingerboard (particularly in tap mode), with basic strumming rather than picking. The neck is very wide and the frets evenly spaced all the way up, so there's a bit more stretching needed, especially in comparison to an electric neck, and if you have small hands it could be a bit discouraging. It's its own thing, and the more you try to play it like a physical guitar, the more frustrating you're likely to find it. But a complete novice can pick it up and play a basic blues box in tap mode with pressure bends, which is very much not something you can do with a physical guitar.

I am in somewhat the same situation as the original poster.  I did some rhythm guitar strumming in my younger years.  But didn't stay with it.  Now I just want to occasionally pick a guitar up and lead some simple song leading for Christmas carols and the like.  Definitely not frequently enough to develop calluses.

However, I now see that things like Barre chords are not possible.  Is this because the fret board cannot electrically send more than one press on a "string"? Or perhaps the software doesn't process the multi-press on a single string.

I also wonder about the bridge triggers being less sensitive, and how it affects strumming.  Can an experienced guitar player pick the Instrument 1 up, and immediately use it for rhythm guitar strumming without difficulty?

The I1 has no problem handling multiple string presses; the issue with barre chords is that a barring finger exerts a very uneven set of pressures across the six strings, and a pressure-sensitive electronic instrument has to make tricky decisions about what level of pressure qualifies as a fretted note. On a physical guitar your barring finger can feel how much each string is depressed, but that's very difficult to get from a rubber fretboard; haptic feedback from the I1 works well at fingertip level, which is why the I1 is so brilliant for expressive solo lines, but the side of a finger is much less sensitive. It's probably possible to train yourself to play barre fingerings consistently on the I1, but it'd take practice; it's not one of the things that's a straight translation of existing guitaristic techniques.

How playable you find the bridge triggers depends on your individual strumming style; many guitarists find it completely effortless, but my own experience (as a fingerstyle guitarist with a very light right-hand touch) is that you need to strum quite enthusiastically to ensure all the notes reliably trigger. You'll also tend to find that the level of triggering for the six virtual strings doesn't map elegantly on to the velocity range of six strummed physical strings, so it'll always sound a bit off-natural. But it's perfectly playable if you're not too bothered about realistic nuance.

Another beginner question: Does anyone know of an app that works with Instrument 1, something like "Learning Portal for Jamstik", that can be used to learn chords with a MIDI guitar? Doesn't have to be fancy, but should display and recognize properly played chords...