Many and in fact all the Samsungs I run into don't vary the volume on the headphone jack with the remote. Samsung in some models has a setting to change that. You know your set better than me so look for that.
That said I used a bookshelf speaker set on my Sony which I would buy again. Here's the amazon link.
As to connection, I think you have a good bead on that part.
I have a 42" Samsung TV and as far as I can tell it only has a headphone output, as well as two HDMI inputs. I am looking to get a pair of speakers to use to improve the sound and I am not very interested in sound bars. I am just wondering what my options are in terms of connections etc.
I feel like getting a receiver is slightly unnecessary for what I need, currently I am using two active Yamaha speakers connected via a somewhat dodgy connection (two jack leads from each speaker output, connected to a signal splitter in the headphone output to get the L+R signals)
If there is a decent signal splitter that I can get that splits the L+R output from the headphone output , and connects to two separate 6.3 jack leads, that is one possible solution.
Thanks for any advice people can provide.