You need a decibel measurement for movies , if you listen louder bookshelves will strain avr . But if not then there fine , your current speakers are very nice tho smaller then today’s q series but still better center has two woofers . How long ago did you purchase that sub too late for return ? You may need to add something more substantial for theater 🎭... ouch Canada 🍁 subs are harder to find ...

KEF - R600c Center Channel Speaker
www.musicdirect.com
In pics sub looks big , ehh if it’s loud enough. I don’t see anything wrong with your speakers unless you dislike kef ??
Panasonic makes OLED??? Can’t buy them in USA 🇺🇸 I’m using a 42” plasma in a bedroom it looks better then my 4k tv did ... I thought panny quit tv Business years ago ??