yeap i changed everything on mine, and do the same on all others i do now because recently we did a mk4 non turbo to 1.8T using customers own donor etc, i told him to change everything but he wanted cheap option and just to swap it all over so thats what we did
i did clean it all so it looked ace but i told him i was not responsible for sensors or belts going wrong. also told him the K03S was passing oil quite bad and needed rebuild which is much easier to do when engine is out of the car...
guess what, car has been nothing but hassle with sensors going wrong, leaking turbo which i told him to have re built (£ a few hundred quid !!) no boosting issues due to split pipes etc.. all stuff i told him to replace..

he is now having to do stuff which would have been p1ss easy to do when the engine was out and regretting not taking my advice
Do it once, do it right... cutting corners = a fail at a later date and a fail = Regret
