Mesh Analysis with diodes? stuck

greygoose

Hi,

I'm pretty confused about mesh and nodal analysis when there are diodes in the circuit.
I want to calculate the maximum amplitude that pass through resistor R3 and the maximum amplitude of the voltage drop across resistor R1.

In the schematic below the voltage drop across the diodes are in total 2V when conducting and the voltage source is 50Hz, 100V AC.

I also have another question, when there is a capacitor in a DC circuit and I have to use mesh or nodal analysis, should I just take that the capacitor is an open circuit?