I absolutely wouldn't want a trapeze - there are plenty of good trapeze asymmetrics out there (and lots of crap ones too). I'm not saying it needs to be a docile as a 200 (or Mirror??!!), merely pointing out that the 59er tried chasing ultimate performance and didn't sell. The 200 compromised performance and does sell. And there is a reason for this. (Edit, to add that the 200 has small sails but is a tippy little bugger)
As it stands I think the 59er IS the wrong boat, not just for me but for plenty of others. And that is a shame. It has the newest generation Bethwaite hull around, so is bound to be great. It probably has a very good rig, but it looks a little dated with the pin head. Not essential to change it, but why not eh? But the thing that appears most offputting is the size of the kite - it is supposedly a hiker aimed at pensioners but has a kite that is bigger than the twin trapeze RS800.
I don't subscribe to the theory that the 400 killed the 59er. The 400 had been established for many years before the 59er came along, so the price differential can not have been a suprise to Ovi's/Bethwaite. And the 400 is only around in the UK, so that wouldn't explain the lack of take up elsewhere in the world (even Aus).
Pretty sure that its UK builder Chris Turner of Ovi fame rated the 59er as a great husband wife boat - pretty importnant in this day and age and the reason why the merlin rocket is healthier than certain other esoteric 14 ft development classes that aren't any more expensive in real terms. Sure the 400 was around first, but I suspect that knocking that off its perch wasnt at the front of FB's mind when developing it. nonetheless a pricier (but about 40kg??! lighter) boat came about and we all know that people buy on price first.
GS - mixed team stuff apart, a reason for the traction in the UK of the likes of the RS200 is that with its crappy little kite and modest pace, you can hold the kite around far more legs on a crappy club RTC course on a crappy gravel pit in the midlands somewhere, And its still a laugh on open water ww/lw esp in big fleets, which they get at opens/nats, so its relevant to all arenas.
Even the RS 800, with a smaller kite than 59er but far more RM, is far too quick for a lot of smaller clubs courses, and will hold its kite on say 30% less reaches than a RS200, all despite being designed around mixed crews (see a pattern here.. ) It'll burn a crew out quickly hoisting and dropping, especially those marginal drops that you do at the last minute because a cow farted in a field and suddenly you can't make the gybe bouy. So the wife/girlfriend will be put off / intimidated / knackered and go back to the RS200 / Merlin / N12
Suspect that the 59er as designed would be just fine mixed teams on expansive water and/or ww/lw, but sadly that isn't the reality of most dinghy sailing in the UK, so less herd mentality and thus critoical mass needed to achieve class traction.
Don't doubt you could do better than original rig - square tops are just plain better, but these SMOD rigs are always too bendy even in the first place, but procuring a modern fitted developed rig will cost an arm and a leg so if you have access to a 29er XX rig then I am sure that would be ok if the "J" measurement is OK, areas similar and you're happy to mess about with shrouds etc.