When we started to hand stitch we went through this question as well. We ordered everything brand of thread we could find (all the ones mentioned in this post) and then some. We tried every combo with multiple brands of irons as well. In the beginning, we landed on Crimson 3.85mm chisels and Vinymo #8 & then #5 thread. I love the look of 3.85mm but after hand stitching a good while we changed to 5mm Crimson chisels and Vinymo #1. I know there are folks that say you must wax the thread but we never have. I find it dulls the sheen and does not server much purpose with the Vinymo thread. We do use Ritza but only for internal panels where the thread will not be seen as it will pound flat much better the the round Vinymo. Think the bottom of internal wallet pockets. Vinymo is every bit as strong as Ritza and has a true round look. It is more elegant but can also look robust. We will be getting a new machine this year and we will be using Vinymo thread in that as well.
Yes, you can hand stitch with Vinymo thread and we recommend it. The attached pics is our Iris Womens wallet in W&C Chestnut. It is stitched with 5mm Crimson chisels with #1 thread.