I am not completely versed on lilypad skimmers, but that one looks broke! The flat piece should be the base to the "can" that is in the other picture on the deck. Or at least, it shouldn't be easy to disassemble (making it hazardous) Why dont you do a search for lillypad skimmers, so you can get a look at what kind you have, or perhaps purchase a different type. I like this one
Amazon.com: Aladdin Skimmer Complete, No-Niche, White: Gateway
It has kind of a small opening but the can is one piece which i like. And you will more than likely have to adjust the elevation so it weirs correctly. I had the best luck "dry fitting" the plumbing between the wall and the skimmer to get the elevation correct. You could probably get any type since the connection is standardized (1", 1 1/2", or 2" pipe size) You dont want to get rid of it since it is your only means of skimming the surface (short of you doing it manually). I would also leave both of those gate valves open all the time to reduce entrapment, Or shut off the pump while anyone uses the pool.
Ah so that’s the name! I had no idea what to call it.
The top is relatively secure, I’ve specifically been taking it off for the pictures to show the pipe underneath. I just realized I haven’t posted a picture of it all together, which I will do later.
It uses two set screws to kee the top on. If put on properly, it’s not super easy to get access directly to the suction port. I guess hair could get in there, but you wouldnt be at risk of entrapment i don’t believe.
I’ll post the assembled picture later. Thanks!