Mostly awful...
Trevor - hmm, it's kind of "old English lord" to me. Not that bad.
Treston - looks like "pressed on". Horrible.
Josalin - don't like it.
Josephine is much cuter.
Trendon - looks like "trod on". I don't like names that sounds like English villages.
Trace - that's a noun, not a name.
Trey - ewww. Like a tray or what?
Jennica - not THAT uncommon here in Sweden, but I don't like it.
Jenny is much cuter.