1) I have a hard time figuring when to move to the next grit level. I'm in learning/practice mode, so the last 2 razors I been working on I've breadknifed frowns out of them and started from scratch. Setting the bevel on the 1k norton, I've been honing till there are no flat spots (checking for flat spots with mag and light)and then I move to 4k norton. For the 4/8k I'm really kinda guessing when to move on. I use the TPT, but it seems like a guessing game. I probably rely most on how easily it cut the hairs on my arm. Does anyone have any advise?

2) What's the deal with taping the spine? Some use no tape, others use multiple layers, others use it on the 1k then use no tape for the rest. I saw one video where tape was used for the finish only.
I get that people don't want to scratch the razors but if your honing the scratches out of the bevel aren't you honing the scratches out of the spine? I personally would rather use no tape. Do you experienced guys see that as a problem?