Welcome back. The text client will always be well supported, and sendcommand
seems a necessity, at least with the current system.
If you want to try anything fancy, you might be interested in playing around
with ctdlsh. It's been in an "experimental" status pretty much forever, but
if you take a look around that bit of code, it should be obvious that its
intended purpose is to provide an administration shell for the Citadel system
that doesn't require either logging in with a web browser *or* logging in
to something that looks like an old-school BBS.
It's far from finished but it has enough in there that you can see its intent.