However once properly set up, you can basically leave things alone and remember only the commands that are frequently used.
Here's a list of commands I commonly make use of in rTorrent including a few semi-frequent ones:
|Backspace||Add torrent in paused state using URL or file path|
|Return||Add torrent and start download immediately|
|^s||Start downloading inactive torrent|
|^d||Stop active torrent, or delete inactive torrent|
|^r||Hash check torrent|
|[Shift] + a/s/d||Increase upload [download] throttle by 1/5/50 KB|
|[Shift] + z/x/c||Decrease upload [download] throttle by 1/5/50 KB|
|^q||Shutdown rTorrent. Force shutdown if pressed twice|
There's more of course, but you'll find that there's very little else you'll need unless you're a control freak. If you find you need more, here's the rTorrent user guide.
A rTorrent command reference
Getting started with rTorrent on Ubuntu