I really liked the canal path. There were only short sections towards the end that got uncomfortably bumpy, and even they weren't that bad. The worst bit for me was the short stretch of badly broken up tarmac on the road just after you come off the path.
I had forgotten about that "road" - yes that was worse. I think I'm mainly disappointed that we can't manage to do these types of path better in the UK, as you say it was perfectly rideable at least in the dry, but could be so much nicer.
Yes – the routes into and out of Hythe come very close to intersecting at Newchurch (just after the info control), so you could if you wished use the canal path in both directions... or neither.
We did think about taking the canal path only as far as the first bridge and then using some of the outbound route, but decided to follow the route sheet.
Which reminds me to give a big thumbs up for good clear instructions, being GPS-free a good routesheet is much appreciated.