as I've said... what you see in the MCP mixer for sends depends on the theme you are using... most have a knob... with a 'slider' that shows the amount the send is set to...
some use my trick to not see a knob and give the impression of it just being a slider....
go to the reaper stash and search for CIRCUS... you'll find a theme called CIRCUS NEXT 9, you have to download two rar fies, part 1 and part 2 to get it... try it
also the themes by this person have that kind of sends slider:
http://tritonreaperthemes.webs.com/
but the premium ones cost a few bucks.... or try a free one
and again, I'd try the HeDa VIP track inspector if I were you