I would appreciate some advice since I'm new to this, does the cassette and chain look OK? It looks like there is some wear on the cassette but is it time to replace (imgur.com/a/9EFdEtF) ? I can take more pictures if that helps.
good call. The FX bikes are good, but I find them kinda slack and slow handling (not sure the geometry is good for higher speeds anyway - seems to like the 10-15mph range).
For the chain - you need a chain tool to check it. Of course your LBS will check it for ya for free - cause they will be happy to sell you a new chain. If the chain is fine the cassette should be fine. Long as it doesn't skip teeth under power.