The Bicycle Dutch blog focusses on Utrecht and 's-Hertogenbosch (Den Bosch) because the author lives and works in those towns. But he also goes on trips to other parts of the country and hires bikes there using the OV-Fiets bike hire scheme.
If you are going to take the ferry and want to experience cycling it is easy to take your bike with you. You could cycle to Rotterdam city centre from Hoek van Holland along excellent bike paths or take it on the Metro.
I think it was his channel that I found a video on cycling in the Netherlands, it certainly inspired me to get over there. Not Just Bikes was another channel with some videos that encouraged me to check out the Bicycleways, which do look good. It was that same channel that I watched a video on about cycling in Copenhagen, it really is nothing like the Netherlands there. I'd feel safer cycling in London than in Copenhagen! Birmingham would be less scary in places too!
The blue and yellow bikes, they do look good and I would certainly consider using them.
You have answered a question I was pondering last year, when I was last considering cycling in the Netherlands, about taking my cycle on the Rotterdam Metro. I am very happy to hear that I can take my cycle on the Metro, although I would of course look to cycle into the city first. As you can probably tell, I have plenty to research but it is high up my list of places to go.
Incidentally, when I last looked at doing Eurostar to Amsterdam, I couldn't take a cycle on Eurostar so I lost interest in using the railway to get me to Europe. When I go, I will want to do some rural cycling and not just in the cities after all, so taking my own machine with me is critical!
And for good and typical examples of good cycling infrastructure and culture, also look at smaller cities outside the west of the country. Historic cities with good cycling infrastructure and planning are for example Deventer, Zwolle and Groningen. Some of these even have a modal split for cycling of more than 50% for trips starting in the city!
If you are interested in town planning as well, I can recommend Houten. It’s a sort of new town close to Utrecht and totally designed around using the bike and train for daily life. Cars need to travel around the neighbourhoods while on the bike you can get anywhere using the shortest route. The expansion of the town was built around a new railway station and they repeated the same principles in the new part. So now, Houten now consists of sort of two towns with bike as main mode of transport.
Groningen looks really nice to cycle in, I watched a StreetViews video filmed there and it looks absolutely incredible. I never got there on my Benelux InterRail, but now I've seen it I want to go and explore. I suspect I could spend a whole week cycling in the Netherlands and still not get all that much done.
Zwolle does look good, I've not seen a lot of it but I do remember bits of the little town at the end of a DMU branch line (as it was in 2013, it may have been electrified since then). Kampen I see it was, and my visit was way back on 12th March 2013. According to my video on YouTube, it was a pair of noisy Class 3400 DMUs:
From what I can vaguely remember, it looked a nice place too. So did Harlingen, I only had a quick look around when I was there, the priority at the time being to cover as much track as possible as well as travel on as many different trains as possible. I would need to go back and revisit I think now, 9 and a half years later.
Utrecht is firmly on my list to investigate, and I have noted that about Houten. I've also noted that from the other poster about Almere, which I have heard of but not explored.
Anyone any views on Maastricht? I stayed in that area on a railway adventure way back in 2014, and while I remember some bits of it I haven't many clear memories other than arriving with a load of snow around!