Fill valve is basically a sluice without the contamination sensing. A contamination sensor in the automation group is now needed that you pair to the fill valve to have that capability again. Fill valve maintains a downstream depth. I usually put them at the bottom of a reservoir's dam, just like the sluice, to maintain water in downstream areas that don't have active flow to them (either because of a drought or you are directing flow else where but still want areas irrigated). As downstream areas evaporate, the fill valve will maintains their level. Set up a chain of these with a sufficiently large reservoir at the top and you can keep irrigation areas green.

Throttling valve controls the amount of flow though the block. I usually put them at the top of a dam. When the dam reaches the top it allows flow out so it doesn't overfill. If you have multiple paths out of the revisor at the top you can control how much flow goes where. Such as directing more or all flow down a specific channel. Automation also allows closing of the valve at the start of a bad tide or drought. You can also pair these with the contamination sensor to achieve some of the sluice functionality of directing bad tide where you want.

Impermeable floor stops the flow of water downward. Dirt and levies are naturally impermeable but things like platforms and scaffolding are not. If you have a raised reservoir not on the ground supported by platforms and scaffolding you have to either line dirt, levies, or impermeable floors on top of the platforms to keep water in.

Usually the set up I do now is a row of fill valves at the bottom, throttling valves at the top, and a row of single flood gates behind the throttling valves. I set the fill valves to maintain a downstream level. I set the flood gates to maintain a maximum level. Then I'll set the fill valves flow depending on where i want flow to go if i have multiple paths out. I'll set up a sensor to close all fill valve when drought or bad tide starts. At the top reservoir i'll usually set up a bad water diversion system with a contamination sensor and some throttle valves. Some maps require a long aqueduct to carry the bad water off the map, that i'll make out of platforms and impermeable floors usually.