中辞典 has "if anything" as its first translation.

Added meaning "if anything"
This is commonly a suitable translation in my experience, and one which is often the only feasible translation in context.
Example: 少し前からネタ切れで面白いのが思いつかない。むしろ今のつまらないネタを視聴者に許してもらえるのがありがたい。
"Rather" and "instead" do not fit here at all, whereas "if anything" is spot-on in terms of nuance.

@@ -21,0 +22 @@
+<gloss>if anything</gloss>

You are probably referring to the sound clips linked in WWWJDIC. They are not part of this dictionary; they are from a Japan-based Japanese language education site, and have been recorded by native speakers. I guess we'll just have to live with variant pronunciations. You say tomato, etc.

Casio EX-word DATAPLUS 6 XD-D100000

My electronic dictionary (Casio EX-word DATAPLUS 6 XD-
D100000) gives me a followwing intonation after む, but 
your online intonation is flat. In my way of expressing 
this Casio is む↘ろ　vrs your むしろ444し

Google ngrams (confirms the kana is more common.)