Chess Calculation Exercise 1

Here is a position I have just looked at:

I set up the board to the above position and gave myself about 20 minutes and wrote down my calculations. Of course without moving the pieces, as the objective is to improve calculation/visualisation. I will record and share my efforts and give the solutions in the next post, 'Chess Calculation Exercise 1 - Solution' just in case anyone wants to have a go themselves. The reason I am writing down my thoughts is really two-fold, first so that others might like to do the same and also to record my thinking to look back on at a later date.

Thanks.