I'm also a S1 beginner and a REAPER user. I'm not aware of a way to create silence within items yet as easily as REAPER does, but what I've been doing in similar situations is to use either the "Range" tool or the "Insert Silence in Loop" function.
These might not be exactly the way you had it before, but perhaps they can help you come up with an equivalent workflow.
The range tool can just highlight and delete an area, no splitting needed. If you hit ALT + R it extends the range fully vertically across the entire song, so you can delete across all tracks without scrolling.
For the "Insert Silence in Loop" function, it affects all tracks and I think it's only in Keyboard Shortcuts menu, so I assigned it to "\". Just create a loop in the ruler (similar to REAPER) and fire the action. Here's what it looks like: