Hello buddy,
1-Lengthening takes two to three months (1mm per day or so for a theoretical max of 9 CM)
2-Nails can be there for life if you want that. I have plates and screws in my arms. Usually nowadays we don't rove them unless they cause problems.
3-Precice 2 is not designed for weight bearing, so you won't be moving until after some bone consolidation which is around 4-5 months after surgery. Stryde nail - but I have heard there has been a recall for problems with it and it is probably costlier - is designes for weight bearing. Thus, you can move with crutches the very next if so you please.
