One should also remember that staking is a random process. The '3 days' shown in the wallet is supposed to be close to the average time to stake. On the other hand, fluctuations around the average could be non-negligible. A rough estimate of the variation for your case would be on the order of days. So there is a small chance it would take in excess of a week.
Also depends on other variables, like total network weight and difficulty. Hard to predict. Getting more coins isn't a terrible idea if the uncertainty bothers you (i.e. not being sure everything is configured correctly if it's taking longer than expected .. although in your case everything looks fine).
Yes, I'll be getting more coins, but not only because of staking. I think GRC will grow in the longterm, and also I plan to use Gridcoins to make/receive payments.
I think need for this also will raise as more people will be using Gridcoin
True. Those are all great reasons. I have a small investment myself.