OP, if you search this forum you can find a lot of discussion on this topic. You will see a lot of haters response about training wheels. I've gotten the same replies in the past when I asked that question.
I wasn't comfortable going open oar on my boat when I had my pins and clips. I like the ease of oar rights, but wanted an ability to try open oar when possible. I went with convertible oar rights, which flip up when you want an open oar.
Here is a link if you are interested:
Oar Right - Convertible Oar Right
Among my group of friends I see all three types you have listed and everyone boats just fine. It's whatever your preference really and what you are used to. Don't go for open oar because of "manliness" and having arms tired every night.