Voltage drops or surges if they are too large can cause problems.
Every motor draws more current when starting than it needs to operate. So that alone is a problem for some systems.
You use a fuse to start the pump, instead of a switch?
I've seen it in practice and in our field.
Although I'm always for a good ridge switch for the pump.
Although I know they make all kinds of them today.
It's hard to give any advice to someone who isn't an electrician.
Be careful.