yes,its normal.next time watch for small cracks and chuncks of belt missing off the ribbed lines,i carry a spare,as i travel a lot.

The idler on the tensioner can't be replaced unless you drill the original one out and re-tap it, the top one needs doing the bottom one i'd only do if it has lots of movement or is screaming, top's part number for gates is a 38001 (nuline EP017) and the bottom one is a 38024 (nuline EP018) this one is only poly for gates has it's a grooved pulley.
These's can be had cheap if you know where/who to ask.