Re: permanence, read up on “cementing” gains.
Re: top 1/2, sure, that’s what will get the highest pressure as you move your stroke forward. As long as you’re taking it slow and following the newbie routine, you should be in good shape. But you should read up on physiologic indicators (“PIs”) to make sure that you’re on the right track.
Re: bottom head spots, the “glans” is the entire head:
The spots you’re talking about might be “pearly penile papules.”
If you just have some mild soreness there, then you might be ok — but greater pain would be a negative PI and you should maybe take some rest days until it stops. PE is a marathon, not a sprint.