Yes, that looks like it's designed for low pressure and you can see the NC and NO symbol if you zoom in, and it has the three contact terminals to configure it one way or tother. As you say, it is a bit on the chunky side, vut could probably mount this on the end cap, so it won't take up too much room.
The limit switch isn't absoultely essential, you can run without one, after all the limit switch shouldn't activate under normal conditions if your boat is trimmed well. However there is the problem of overfilling if the pump stuck on for some reason, and peristaltics in particular can reach dangerous pressure levels, more so than say a geared pump or centrifugal type, as essentially there is zero 'slip'. You could circumvent this by placing a pressure relief valve in the WTC, set to trigger at say 20 psi e.g. well over what it should be under normal conditions.