Well reduced fracture followed by physiotherapy usually gives very satisfactory results.

No not much problem Wil happen if perfectly done

Any fracture or tissue damage may leave some trace for longer period of time. But vigilant care and treatment can cure this as much as like new. Also good surgery can prevent early onset of OA and can preserve your youth for longer age. Factors affecting outcome- Reduction, Postoperative infections, Postoperative rehab amd physiotherapy.

Whenever a fracture in any joint surface including tibial plateau, id fixed with surgery at-most care has to be taken to recreate the joint surface. There should be a variation of maximum of 2 mm between the fragments in the surface. If thats achieved then there should not be any issues in old age.If there is any variation in the surface then it leads to wear and tear in old age.

    If the fracture is well reduced and tibial plateau height is achieved,there will be no problem.     Do you have family history of diabetes,if yes then if you get diabetes in future,there might be higher chances of infection,so better to get the plate(implant) removed once the fracture has united.

Depend on surgery