Auto bilge system + monitoring

[andre26]

Hey guys,
I have a plan on how to monitor my bilge pumo plus adding a Auto-Off-Manual selector, not 100% sure on how to proceed and i am no elechtrician by any means

So the idea is to have a 3 step switch (On1 - Off - On2): On1 dirrectly to pump to have "Manual", On2 connected to float switch and float switch connected to pump to have "Auto".

First doubt, should i add Diodes so that current doesn't go back either to On1 or On2?

Then, the monitoring, the idea is to add a relay on the + terminal of the pump, that when on triggers the NO circuit of the relay and the relay is connected to the Pico Simarine voltage sensor, so it monitors when on and for how long.
Plus i'd like to know indipendently from the pump if the the float switch goes on, the idea was to add another relay to the end of the float switch like before, but the doubt is that that end could be energized by the pump being on and losing its indipendence, hence the idea of the diodes...

i attached a drawing of my idea

I'm a bit lost thanks in advance for the help !