I totally know how you feel about altering, it seems a little, I don't know, sacrilegious? I put off altering a pair of Dior heels that I had for a long time even though they killed my feet. I am so happy that I went through with it, though. I wear them much more often because they don't hurt and I never notice the alteration (and I am sure no one else ever would either). I've also had to repair my CL Differa's because one of the straps broke and you would never notice. I really think that altering is better than not being able to enjoy your shoes as long as your cobbler feels confident that they can make it look good. I have also stretched several shoes (because I have a high instep - and I would explain trying to get shoes over my feet in the exact way that you did, which is why I suspect that might be the issue) and it has never hurt or altered the appearance of the shoe.
If your problem is a high instep, then I think an elastic would be a great solution. Good luck with whatever you choose and show us the results if you do decide to alter them, I would love to see it.
