You are absolutely correct- it’s an unlikely risk of a leak; you’d have to say not tighten the plastic cap or drain plug quite enough and also forget to close the seacock to do any harm. I’m not meaning the basket is going to explode or the drain plug’s gonna launch across the engine bay
I personally like to eliminate as many of those what if (however unlikely) scenarios as possible, but I’m pretty uptight about safety as I have little kids (which means dealing with any situation on the boat becomes 50 times harder). If you are cool with that setup, which definitely seems reasonably safe, awesome and enjoy the sailing! Nice job on the install too btw, looks great.