How is Gulden being received by the general population in the Netherlands?
0.00002% of the Netherlands know about Gulden as a digital currency. Growth will come with time as more people are made aware of Gulden but there is users that post here from all over Europe and US.
Where did you derived that number from if I might ask?
Anyways, in my experience, Gulden is received with a smile. Mostly such conversations are started with Bitcoin, since that's an entity most have heard of; but when I tell them that there is so much more, I tell them of Gulden as well. Guldens were our nations currency before the euro, so when I tell people about it how it still exist, I always see a little sparkling. But that's probably due to my generation and the generation I am conversing with on such occasions
At least from some I know whom I have spoken to have been purchasing Guldens, and a few have even started mining them... 
I am looking for a good coin that isn't popular, if it's popular already it's not a good investment. My aim is to hold a currency where the purchasing power increases over time, with fiat the value of your money decreases with time and the stock markets are fragile at the moment... I have looked into Gulden rewards at 100 / block and no halving? Will the total amount be 1.68 billion coins or will the 100 rewards carry on forever?
100 per block until the original target of 1.68 billion is met and then rewards stop with the idea being that fees will be sufficient at this point. This will be a long way in the future though.