First of all, it seems to be a "horror setting". Well, my first advice is that you will keep it that way, and do "horror werewolves". You could be tempted to make werewolves "teen wolf style" or something similar, but it doesn't work, as it has been largely demonstrated in fiascos like "Wolves", "Skinwalkers" or the latest reboot of the "Howling".
The second advice is that you work with an actress who would enjoy the experience, or at least who felt comfortable working with make-up/fx simply because half of a good transformation scene is the performance.
The third advice is that sometimes less is more. I mean, don't try to do something you are not able to do. You will not have John Landis/Rick Baker to get the things done. Or the budget, being honest. Sometimes it is better some "obscure" or darkened shot than showing an obviously fake prosthetic, but if it looks just "a bit" fake it would be ok... yours is the decision of showing this or that.
About the TF itself, the "painful" and "unwilling" TFs work better simply because they leave more room for a good realistic performance. This connects to my second advice. And finally, about the nudity, for me it is almost "mandatory" BUT it is not necessary to see anything. I mean, through the proper usage of camera angles you can film a TF scene with a nude performer without showing "anything"... I mean, it is a bit more tricky to film nude women, but it can be done, for sure.
Well, thank you for asking for our opinion, I wish you the best for your adventure, sadly you will need it... this is not cheap, you know
.