Full mouth veneers/restoration - is this a reasonable treatment plan or am I making a mistake?

While in another case I would suggest orthodontic treatment first, in your case, given the circumstance of tooth resorption, I think it is a good option to perform veneers to make a wider smile and improve shape and color.

That is a very reasonable treatment plan, except I would have to see the root structure of all of the teeth. This is very complicated and time consuming type of treatment. You must be patient and not want an instant change. Opening a bite with onlays or crowns requires a bit of time in Temporaries to let your jaw get used to the new bite. There is a lot of personal input from you about what feels comfortable and what is too much and a forced opening. Then when the amount of opening is correct, the dentist will have proper measurements for the exact height of the new crowns or onlays. Only then can the final treatment begin. This is a complicated process. When done incorrectly, this can be a disaster. Have good references, and be sure your choice of provider isn't trying to do the whole thing at once, and will take the time needed with you. Good luck.