First issue: linnath would mean "(all) songs" (-ath is the "collective plural" suffix, not plain plural) rather than simply "singers". Quenya has Linda(r) for "Singer(s)", whose direct cognate would indeed be lind in Sindarin (and become linnath with -ath), but this word is already being used for "song". That is why the attested (partial) cognate of that term in Sindarin is rather Lindel (or Glinnel). But these terms refer to the Telerin Elves, not singers in general. So a combination of linna- "to sing" and the agental suffix -or would be more proper. That gives linnor, whose plural form would be linnyr.
That "en" should cause what we call "mixed mutation", which means (among other things) that the initial P, T, C(K) of the words that follow it need to become B, D, G. Also, "en" receives elision in these cases, which your first line misses although the other two show it. Hence my correction of "en-taur" to "e-Daur".
As for changing glad, the word requires its root to be "GALÁT" whereas we only have GÁLAD which yields galadh. It is an attested word, but there are no (published) documents which explain its etymology and attest "GALÁT", so I deem it unsafe to use. As for changing palan with haer, the latter is more fitting for the sense that you wish for the name. That should be all.