Good evening Old Duffer, we don't expect you to keep up with the elite master builders, quite a lot of us take ages to complete our models.
I have severe arthritis myself which controls the pace of my builds.
But the feeling of fulfilment at seeing the finished model is what keeps me going.
We all try to help each other, don't think as a newby on here you can't offer suggestions.
With your mobility problems you could find easier ways to do things that we don't know about. YET.
As for your plastic prop if it's the correct size and pitch it will be fine, props can be changed so easily its often best to wait and see how it performs before going to unnecessary expense.